Dr. Satchin Panda: Intermittent Fasting to Improve Health, Cognition & Longevity | Huberman Lab

welcome to the huberman Lab podcast where we discuss science and science-based tools for everyday life I'm Andrew huberman and I'm a professor of neurobiology and Ophthalmology at Stanford school of medicine today my guest is Dr Sachin Panda Dr Sachin panda is a professor and director of the regulatory biology laboratory at the Salk Institute of biological studies his laboratory has made numerous important contributions that impact mental health physical health and human performance for instance his laboratory discovered the neurons in the eye and neurons within the brain that regulate our so-called circadian rhythm circadian rhythms are 24-hour rhythms and everything from gene expression to the overall functioning of tissues our levels of mood and alertness our ability to sleep appetite and much much more in addition over the last decade Dr Panda's laboratory has made critical discoveries in terms of how our patterns of eating over time impact our biology and our health in particular his laboratory Pioneer discoveries related to so-called intermittent fasting also sometimes referred to as time restricted feeding today Dr Panda and I discuss how our circadian behaviors everything from when we wake up to when we view light to when we avoid viewing light to when we eat and what we eat and when we socialize and how we socialize impacts our biology and our psychology energy and how all of that has a strong impact on our health during today's discussion you will learn how restricting your feeding to specific periods within each 24 hour cycle or perhaps even exploring longer patterns of fasting and eating Cycles can impact everything from the health of your liver to your gut to your brain and how all of that impacts things like mood and your ability to perform cognitive work indeed today's discussion goes deep into all aspects of intermittent fasting AKA time restricted feeding we talk about the basic science as well as the recent clinical trials that have explored time-restricted feeding in a diverse range of people including men women children people with diabetes people who are otherwise healthy and much much more I'm quite aware that intermittent fasting is a topic of much debate these days we go deep into that debate and by the end of today's discussion you can be certain that you will have learned all the latest and all the details all all made very clear to you thanks to the incredible expertise Discovery and clear communication of Dr Panda as some of you may already know Dr Panda has authored several important books on the topic of intermittent fasting and how it can benefit various aspects of Health those books include the Circadian code and a more recent book the Circadian diabetes code both of which we've provided links to in the show note captions in addition if any of you are interested in learning more about Dr Panda's work including seeing his Publications and reading those Publications we're supporting his laboratory you can do that by going to his laboratory website which we have also linked in the show note captions before we begin I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford it is however part of my desire and effort to bring zero cost to Consumer information about science and science related tools to the general public in keeping with that theme I'd like to thank the sponsors of today's podcast our first sponsor is hvmn Ketone IQ hvmn Ketone IQ is a supplement that increases blood ketones I want to be clear that I am not following a ketogenic diet most people fall into this category they are not following a ketogenic diet they are omnivores and they do eat carbohydrates so their standard fuel source for the brain and body is not ketones however I found that by taking Ketone IQ which we know increases blood ketones I can achieve much better focus for longer periods of time for any kind of cognitive work and much greater energy levels for exercise especially if I'm going into that exercise fasted and find myself a little bit hungry when I start that exercise this is no surprise we know that ketones are the brains and body's preferred fuel source even if you're not following a ketogenic diet so in other words I and many other people are now starting to leverage endogenous ketones as a fuel source for the brain and body and yet we are not following a ketogenic diet and of course if you are following a ketogenic diet Ketone IQ will further allow you to increase your blood ketones as a source of brain and body fuel if you'd like to try Ketone IQ you can go to hvmn.com huberman to save 20 off your order again that's hvmn.com huberman today's episode is also brought To Us by eight sleep eight sleep makes Smart mattress covers with cooling Heating and sleep tracking capacity as I've talked about before on the huberman Lab podcast there is a critical relationship between sleep and body temperature that is in order to fall asleep and 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be right across the street from one another yeah yeah you remember those days yeah yeah so I'm delighted that you're here um I think we're going to talk about a number of things mainly intermittent fasting time restricted feeding and health but also the many other things that you're doing just before we started recording we were discussing your recent paper in nature uh that involved recordings from post-mortem Human retina so maybe if there's time at the end we can get back to uh your lab has shown that you can essentially maintain or resurrect neurons from uh dead people in order to potentially and eventually provide transplants to rescue Vision in the blind so that's extremely exciting but of course not the main focus of today's discussion so we'll have to uh split it up um the first question I have is how am I supposed to Define fasting and time restricted feeding in meaning when I go to sleep every night I'm not eating so in some sense everybody is doing time restricted feeding to some degree or another yeah at what point can we start thinking about a pattern of eating as time restricted feeding so-called intermittent fasting does it have to do with how regular one is about the start and stop times how do you think about defining intermittent fasting time restrictive feeding and maybe just to simplify the conversation is one term more correct than the other in terms of describing this incredible pattern of feeding well you know that intermittent fasting covers many types of fasting um so actually it started long time ago and it's embedded into the history of caloric restriction um almost 100 years ago people showed that if you reduce calorie intake in a rat then that rat can live for a long time and in those experiments the calories were reduced every single day and that led to the idea that if we cut down our calories by 20 percent say then we can potentially live longer by doing two things one is preventing is related disease or even if we follow fall sick maybe we can accelerate cure and keep the repair mechanism going so that we can live longer but it was very difficult to count calories every day and reduce maintain that um I must say that it's not that calorie restriction is impossible or we are not doing it in fact a lot of us we do um count calories in our subconscious mind means every time you took out it you took out we take out a soda bottle or something I'm looking at it okay or in 60 kilocalo or 30 kilocal or zero kilocal we are doing that so the point is it's it's we are doing subconsciously some kind of calorie counting but reducing calorie by Twenty thirty percent every single day is not possible for many people so then the idea came in mouse and rat experiment whether they can eat every other day um and in fact this every other day feeding um also led to very similar almost equivalent Health Improvement as continuous calorie restriction um so then the idea was well every other day is a little bit hard for humans but just imagine I would just get to eat only one day and then another day then the idea came well for humans can they eat less for one or two days in a week so that led to this pipe two diet where people can eat for five days and then two days they have to reduce calories so that's also intermittently people are fasting um then as you know Walter longer also came with this idea that periodic fasting maybe four or five days in every month or two months three months you can fast or reduce calorie and he also found many benefits of calorie restriction was there were those studies on humans many of the studies started it in mice but alternate day fasting five two and um Walters periodic fasting all of them have now been done in humans not for longevity of course because cannot do this for a long time but for weight maintenance for reducing some signs of aging or reversing those things have been done so all of them have been done in humans mostly healthy humans and in some cases people with pre-diabetes or some aspects of metabolic disease so that led to the idea that that all these forms of fasting in which the total caloric intake on any given day is reduced for one or more days in a week a month that became that umbrella term became intermittent fasting so if you look up the scientific literature most intermittent fasting involves intentionally reducing calories for at least one or two days in a week or um few days in a month so when we publish time restricted feeding um the initial Mouse experiments and even now most of the mouse experiments we want to test what is the impact of time restriction versus calorie restriction so in these experiments we don't reduce calorie on any day of mouse life so the mice is the same number of calories as the adlibitum FED mice but still they say health benefit so that's why we call it time restricted feeding but since it involves living without food for several hours for some people which is it can be very difficult the initial experiments was done they were done for eight hours of feeding and 16 hours of fasting that kind of became popular and so that that's why people use the same term as intermittent fasting and now if you say intermittent fasting and popular literature or popular media then people usually refer to time restricted eating so now coming back to how do you define time restricted fitting um so the way we have been trying to Define experimentally and also in literature is um trying to confine all your energy intake from solid and liquid food combined within a consistent window of 8 to 12 hours because that's something that doable of course people have done time restrictive trading with four hours six hours and some people even try to eat everything within two hours one meal a day um but the point is those are not feasible to maintain for very long time for a lot of people one question about the six hour versus eight hour versus 12 hour feeding window is it important that the feeding window begin and end at the same time more or less yeah and if so how much flexibility is there so for instance I'm somebody that I am not terribly hungry in the morning I like to drink water usually some caffeine and electrolytes yeah in the period before my first meal and my first meal always lands sometime between 11 and 11 A.M and 12 noon there are exceptions yeah occasionally I'll have a breakfast a proper breakfast as it's called Uh I guess it would be improper if you're intermittent fasting for me um but typically 11 A.M or noon is when I first eat my last bite of food is typically around I don't know 39 PM that's what works for me yeah is that consistency affording me any benefit separate and let's just leave aside total caloric number macronutrients plant-based meat Etc but is there any benefit to shortening that feeding window that we are aware of or extending that feeding window or being even more rigid about the start and end of that feeding window yeah so the start of the fitting window um that's interesting because the concept of time history feeding when I describe animal studies it's feeding for humans it's eating so the concept actually came from the science of circadian rhythm so that means um our body has an internal timetable that's present in every cell in every organ that pre-programs many molecular aspects of the cells that leads to physiology and all that stuff so that essentially there is a predetermined timetable for every cell every organ to do certain things at certain time and the Circadian clocks as you and I know are more sensitive to light light is the most dominant um time Giver so for example when daylight saving time changes or when we travel from one time zone to another time zone we feel kind of crappy because our daily activities uh out of sync from our internal clock so that was known for a very long time but then around the year 2000 2002 there was a famous experiment by Uli sibler from Switzerland what he did he just Fair demise at the wrong time mice are nocturnal their night feeders and when he fed the mice during their time and the liver clock instead of following its own routine liver clock actually started following food so that means by changing our feeding time we can change we can tune our liver plot and subsequently the same experiment has been repeated many times and when we repeated that in 2009 and we figured out Yes actually outside this brand Center called Supra chiasmatic nucleus or scn which is considered the master circadian clock almost rest of the brain even follows when we eat and that came out from Pierre shambon's lab in Europe where they systematically looked at even places that are very close to the asean for those who are who node or some medial hypothalamus or paraventricular nucleus all of this within a couple of four or five millimeters of the scn but they were following food queue amazing so then um and now if we think about it so for example when the daylight saving time changes just one hour change um or one hour change in alignment between our internal time and external time leads to kind of feeling groggy and filling not out of Peak Performance for one or two days so the rule of thumb is when the time Giver changes by one hour then our internal clock takes at least a day to catch up so that means if you're flying from LA to New York uh you're moving through three time zones then on an average it will take three uh three days to catch up with the New York Times for some people it can be even slower and for some people it can be two days but the bottom line is yes there is a decentrality so then what does it mean for the body sorry one of the function of clock is to anticipate when you're going to wake up for example so the blood pressure slightly goes up our heart rate goes up our breathing goes up similarly for food almost every organ that is involved in feeding or eating digestion all of them have clocks so even from saliva production that's the first phase of digestion to secretion of all the digestive juice and the stomach and the absorption of nutrients and liver metabolism everything the whole village expects one you're supposed to eat and they're getting ready for you to eat the first meal after fasting for a long time so that's why it's breaking the fast of breakfast and when that time changes when you change it by two or three hours from one day to another then um sometimes they're like oh food didn't come or maybe um will come at a wrong time we were at the wrong time and then they will track the new eating time so suppose say one day you have been eating every day at eight a.m um I ate at 8am is that when you start yeah when do you when does your feeding Windows shut uh 6 p.m so I eat for around 10 hours okay um and then one day if I switch to 10 am then what happens is a clerk is thinking well the food didn't arrive at eight but it arrived at 10 maybe tomorrow the food will arrive somewhere between eight and ten so we'll be ready around nine and next day if I come back and eat at eight o'clock then I may eat but my clock is not ready to digest that food so that's why this idea is you have to be consistent uh to take advantage of this anticipatory activity of our cloth in different systems to get the best out of it is there evidence that those anticipatory systems and as they relate to digestion help us better assimilate our food I would imagine so I mean if you have the gastric juices that are going to help digest the proteins fats and carbohydrates and uh already deployed at the time when you eat I could imagine that food will be better utilized than if you don't so in other words what is the advantage of having these anticipatory signals in terms of potential health benefits the anticipatory signal is really important from even even from working up um the reason why many people feel not ready completely when they'll wake up to an alarm clock because the alarm clock wakes you up but your body is not prepared so that slippiness after waking up to an alarm clock is due to our body is not prepared for that and then the best example is when the when uh the daylight saving time changes particularly when we have to wake up one hour early uh what happens people who have underlying heart condition um when they're waking up when the body is not ready your heart is not ready and all operations from the heart has to start pumping little bit harder then there is chance of heart attack and in fact people have looked at hospital records and that they find that on those days and there is a sharp rise in heart attacks in car accidents and car accidents too because your brain is not coordinated so you cannot make those fine decisions so that's a great example of anticipatory activity but coming back to digestion one thing is um and this is something that many people might have experienced there are many rhythms in our digestive system and one of the rhythms is our look our intestine has this peristaltic function so it kind of contracts and expands and that moves forward more food doesn't move due to gravity so it goes back and forth and that peristaltic axon actually slows down at night a few hours after our last meal and um so that's why when people eat late at night for example then that food doesn't get digested because there is not enough digestive juice first thing and second even if it gets digested in the stomach it doesn't move properly so then the next morning people get up and think um of course people consume some alcohol very often and then they think that this is Hangover but those who don't consume alcohol then they have the food hangover because it doesn't digest so that's one extreme example where food at the wrong time can um so healthy food at the wrong time can be crap or junk yeah I've um experienced that where if I've worked late or I couldn't eat dinner or something and then I get home I always debate whether or not to try and sleep yeah but if I'm too hungry oftentimes it's challenging and so for me sometimes consuming something that at least seems easily digestible like yogurt or something in a liquid form um is better for me than if I eat a meal I've made the mistake of going to the refrigerator being super hungry and eating a bunch of food at 10 or 11 p.m and then falling asleep and indeed the sleep if I'm tired enough can be quite deep but the next morning I feel just completely physically and and cognitively weighed down so I think what you just described makes a lot of sense so is it so if someone were to select a feeding window regardless of whether or not it falls into classic intermittent fasting time restricted feeding sounds like eating your first bite of food and eating your last bite of food at more or less the same time each day yeah has benefits I have this question you mentioned feeding versus eating and I think it's actually not just a grammatical uh semantic issue um and here's why we tend to think about when you take your first bite of food and then when you take your last bite of food but of course Foods digest at different rates more fat in there is going to digest make carbohydrates digest slower Etc I mean there's all these adjustments to the glycemic index and so forth with Foods in combination I is it better to think about not eating but your fed State and blood sugar so for instance I often get asked on social media does blank break a fast so uh and so I like to think about it scientifically like okay is does plain water break a fast no does air break a fast no um does one grain of sugar of sucrose break a fast well probably not but does one teaspoon of sugar break a fast well you could say yes but transiently like so I mean when we're talking about breaking a fast are we talking about a rise in blood glucose or are there molecular signals Downstream of of a rise in blood glucose that um cannot be reversed in other words if I'm gonna eat my first meal every day at noon and I'm gonna eat my last bite of food at 8 00 pm and at 9 00 a.m for whatever reason I have coffee with one teaspoon of sugar in it I suppose in the strictest sense I've broken my fast but maybe by if I went for a hard run that morning maybe by 9 30 a.m I'm back in a quote unquote fasted state so what is the fasted State really because when I'm eating at 8 pm just to give another example I'm start fasting at 801 perhaps yeah but I have my blood glucose is elevated so I'm not really fasted I'm fed yeah it's just that I'm not eating the verb right okay so um so again I I don't want to get overly detailed just for sake of getting detail but I think a lot of the confusion out there about what breaks a fast yeah is related specifically to this issue yeah which is if I eat a whole pizza after sitting around all day it's very different than if I eat a whole pizza after having run a 26 mile marathon that yeah very different yeah um metabolically speaking so how should people think about fasted versus fed can we be mildly fasted versus severe fasted can we be um fed-ish versus very fed anyway I'll I'll uh stop asking questions now because they all relate to the same theme yeah no these are um very interesting question and then unfortunately as you can as you have you might have seen in life the most obvious questions are often unanswered because it's so hard to do these damn experiments because if you really want to address this in humans you have to bring humans put them in isolation just like you said I can now imagine planning five or six different experiments each experiment should involve eight or ten volunteers it's gender sex and then do it so it's difficult so now let's go back to see how do we let's dissect it in terms of say indirect calorimetry so for example indirect calorimetry is based on this principle that whatever oxygen we breathe in and carbon dioxide we breathe out if we can measure these two then we can figure out whether our body in total we are not saying whether it's the liver gut or fat or muscle in total whether it's consuming glucose or fat as energy source the idea is when we fast when we are without food for several hours then ideally our body will tap onto glycogen first and then do a little bit of fat and then when the body is mostly running on fat then that ratio of CO2 to oxygen will come to 0.7 [Music] um but what is interesting is we can do these experiments in mice so we can go to mice and ask okay so what happens in mice so and mice mice are a little bit very different because mice are not simply little people they are the metabolism is different they store relatively less glycogen than humans do in terms of total metabolism so they overnight within 12 to 14 hours the rer respiratory exchange ratio or this ratio will go from one when the consuming mostly glucose or carbohydrate as energy source it will slow down slowly go to 0.7.75 it's after 12 to 14 hours they're kind of mostly running on fat so now as we give them food um within 10 or 15 minutes they are not actually consuming couple of grams of food they might have consumed say 100 or 200 milligram of that child so which is less than say five percent of the food and then the rer will immediately begin to rise as if that small amount of food stopped that fat burning process and cranked up the carbohydrate burning process when you say fat burning process you mean body fat stores being burned right not dietary fat correct yeah so it's all body fat means that that's why I said um we don't know where that fat is being burned because we are just measuring how how much mice is breathing in and out um so for example it can be from the Skin So subcutaneous fat or belly fat but not dietary fat no by that time the dietary fat is already absorbed and digested and hopefully it's sitting in the liver or adipose tissue somewhere but it's the fattest body fat yes thank you yeah the reason I ask is that nowadays I think more than half of the battles about nutrition that I see online relate to this issue where I won't name names but someone will come along and say low carbohydrate diet allows you to burn more fat and the more nuanced people out there will will say well that's true but you're also talking about dietary fat you know the word fat can confuse people I realize you're not doing that you are certainly not one of the people guilty of doing this but indeed you eat more fat you'll burn more fat but that doesn't mean you'll burn more body fat in fact I think the day does say that under conditions of caloric restriction you'll actually burn less I hope I don't I'll probably get I'll probably get um pitchforks uh through the mail toward me on on that one but but I think that's true whereas you know people who consume carbohydrate can still burn body fat even though the majority of the fuel they're burning is from carbohydrates so yeah so here in this case for example from mice we know that as soon as they start eating um the area goes up coming back to your question what would be ideal for us to do the experiment would be okay so we'll go back to that and then give the mouse maybe 100 milligram of food and Mouse runs around in the case and then we'll continue to measure to see how long it takes for the mouse to come back and then so that's one husband so now let's say um let's stay on this and then I'll come back and talk about non-caloric food and whether that is considered I'd like to take a quick break and acknowledge one of our sponsors athletic greens athletic greens now called ag-1 is a vitamin mineral probiotic drink that covers all of your foundational nutritional needs I've been taking athletic green since 2012 so I'm delighted that they're sponsoring the podcast the reason I started taking athletic greens and the reason I still take athletic greens once are usually twice a day is that it gets to be the probiotics that I need for gut health our gut is very important it's populated by gut microbiota that communicate with the brain the immune system and basically all the biological systems of our body to strongly impact our immediate and long-term health and those probiotics and athletic greens are optimal and vital for microbiotic health in addition athletic greens contains a number of adaptogens vitamins and minerals that make sure that all of my foundational nutritional needs are met and it tastes great if you'd like to try athletic greens you can go to athleticgreens.com huberman and they'll give you five free travel packs that make it really easy to mix up athletic greens while you're on the road in the car on the plane Etc and they'll give you a year's supply of vitamin d3k2 again that's athleticgreens.com huberman to get the five free travel packs and the year supply of vitamin D3 K2 so there is a famous experiment that was published last year by jotakahasi Islam and it came out in science and that relates to caloric restriction and we kind of started with this idea we started to discuss on that the rat experiments were done with caloric restriction and researchers get reduced calorie consumption by 20 or 30 percent and get that food the rats and then subsequently mice and they all lived longer what is interesting is in all those experiments the researchers came and gave this bolus of food at one time whereas the adlibitum FED mice or rats they had access to food all the time so they're eating all the time and then these rats were given 20 percent less and what happens is this mice or rats then I'm going to take that less food which is restaurant now and just eat little bit of lunch and then snack after three hours or snack after three hours they double up all that food within two to three hours maximum four hours food is gone so they're sort of on the omad diet the one meal a day yeah they're almost like in one meal a day three to four hours food is gone or you can sit there on four hours eating or feeding and 20 hours fasting um so then the question became well the benefit of caloric restriction as we know is it due to reduced calorie or time restricted feeling or timing there is a timing component to it that they are eating all of that within three to four hours and then there is a long fasting and this is a difficult question to answer because now you have to ask this poor grad students or technicians to come and split that food into eight or ten or fifteen different small portions and then give them to mice in every two hours who actually published the first paper in 2017 showing that most caloric restrictions I mean he used the protocol that was used by Kelly restriction field it actually creates a condition of time restriction so he saw that and then he went back and worked with Engineers to come up with the smart kids where he could actually tell he could program how much food is given to mice at what time of the day or night completely programmed so then he took this uh for example suppose say the adlibitum FED mice it's five grams of ciao in a day and if you want to reduce calories by uh 20 percent and the CR Mouse should get four grams of food and it divided this into 9 or 10 meals and then give them in every 90 minutes so in this case they're eating small meals throughout day and night so there is no fasting so you can say that well this mouse actually is not getting into fasting because in every few hours is getting some food and then he measured how long the mouse is going to live um and he used um accountments this is a very standard protocol people count how many mice have dying on which day and then examine them to see whether they've died because they there was an accident or they actually there was a natural cause and then they calculate at the end what is the half life so 50 survival because that's on an average that's a good indicator because if there is an outlier that will live for a long time then that can skew so what was interesting was the limit unfair mice of course they live certain number of days and then this caloric restricted mice that never got into Super fasting but kind of eating snacking throughout day and night that also lift 10 percent extra 10 percent longer so that means caloric restriction extended lifespan by 10 percent I've wondered about this because recently you know there's been there were a bunch of news headlines about intermittent fasting and and frankly I was frustrated if you looked at one major news outlet they would say time restricted feeding affords no additional benefit Beyond caloric restriction for weight loss yeah then another popular press venue let's call it that same study described as time restricted feeding doesn't work yeah right and then another one maybe someplace um even more extreme you know time restricted feeding um only beneficial because of caloric restriction or something like that so what you've essentially got are three different interpretations of the same data all of which are well two of which are true one of which is false in my opinion but what I think people take away from that is oh time restricted feeding isn't valuable which is not the case it I think for many people it's a convenient way to eat because at least for people like me it's simpler to designate between portions of my day when I'm eating and portions of day my day when I'm not eating as opposed to eating portion control for other people portion control can work but all of that is related to either maintenance or loss of weight none of it deals with the potential health benefits independent of weight loss yeah right so um and so I I think that um if we can segment those out um obviously in humans it's hard to know if a given treatment or experiment is extending life because you don't really know how long people would live anyway yeah right whereas with mice you have some sense of when the mortality was likely to occur so what can we say about time restricted feeding and longevity in terms of biomarkers or in terms of any other indication that people who start and stop their feeding window at a consistent time somewhere between 8 and 12 hours per 24 hour cycle are tilting the scales towards living longer as opposed to living shorter this example of this news article that you mentioned is really interesting because that relates to Joe's Joe takas's study because I described that if you split calories and eat throughout the day throughout day and night then the mice lived 10 percent extra but if you now give Mouse the same caloric restricted diet and fit them during day time whether within 12 hours or two hours then the mice lived 10 percent extra beyond that yes so twenty percent so okay so let me make sure I understand so that uh so that I make sure I understand if you take a certain number of calories and you distribute them throughout the 24-hour cycle yeah it's caloric restriction the mice will live ten percent longer yeah if you however restrict that to the active cycle of the so for humans the daytime then 20 then they live 20 percent long twenty percent so it's not just total caloric intake yeah meaning it's not just important to be sub maintenance and calories for sacral longevity it also is important as to when in the 24 hour cycle yeah you eat those calories do I have that right so now that's still the story is not over because this mice were fed during daytime and they're not supposed to eat that's right so for us it will be the equivalent of being on the night shift and only eating at night but a sub color sub maintenance calorie diet I guess is the right way to say it but when he fed mice during night time when they're supposed to eat and they're seeing this getting the same number of calories within 12 hours or two hours then the mice left 35 percent longer than they control 35 longer so scale to human lifespan which you know we don't know but but a 35 longer would mean that um and again no one knows but um humans now what is the average mortality in the United States yeah so it's around 80 it used to be 18 hours slow uh reduce little bit because of covet but let's take 80 okay so people are then now living somewhere between 25 and 35 years longer but I'm putting some error bars on yeah yeah so that was um really profound but now you pointed out um biomarker and other stuff so now if you look at any given time within that experiment and actually Joe went back and um had a separate cohort of mice very similar and so that he could take tissue samples and of course in this case you have to sacrifice the mouse and he looked for um he did a lot of molecular analysis with non markers for example hemoglobin A1c equivalent or glucose control cholesterol all this stuff he could not find anything [Music] that predicted the benefit of caloric restriction so that means in this experiment whatever we know so far the predictor of longevity none of them could predict whether this um CR only Mouse which throughout day and night that Mouse is going to live less than the night fed mouse that was going to live 35 25 extra does that mean that there are biomarkers related to longevity that we just haven't discovered yet yeah so that's exactly so that means whatever we know so far about biomarkers those he could not use to predict maybe there was a lot of noise maybe he wanted he had to use more number of mice to get that because you know biomarkers are not going to predict in every instance so there is some error what is also very interesting is if you look at the body weight and body composition of all these mice there is no difference in body weight and body composition across all these differences all these groups so it doesn't matter when they ate yeah provided they were submit sub maintenance calorie intake so less fewer calories than is required to maintain their weight didn't matter what pattern of eating they were the same way yeah so that in many ways seems to mimic the human studies where they say look it doesn't really matter whether or not you use caloric restriction or or you start your feeding window in the morning or start your feeding window in the evening or you um or you portion control for sake of weight contr weight loss because you're taking a snapshot of that and then another thing with the human study that we are referring to here um that in that human study people are actually already eating within 10 hours window habitually when they selected these people to have them enroll in the study so they were already eating for 10 hours and fasting for 14 hours all participants had to reduce that caloric intake and they reduced by almost 25 percent the CR group continued with 10 hour sitting window and the CR plus time restricted group had to eat the same number of calories within eight hours so it's just a two hour difference it's just a two hours difference okay so that people I just want to make sure people can understand so in this human study which is the one that I felt that the popular press venues all except one venue um got either semi-rung or badly wrong in terms of their conclusion that was my interpretation anyway was that either people came into the study eating basically in a 10 hour feeding window which goes back to my first question which is that most people are not eating in the middle of the night yeah or if they're on shift work and they are then they're sleeping during the day anyway so they're eating in a 10 to 12 hour feeding window anyway so you're saying they either did caloric restriction portion control within the 10-hour window or another group within the study eight sub maintenance calories so caloric restriction CR as we're calling it the acronym CR but restricted to that to an eight hour feeding window and they didn't see any difference in terms of weight loss yeah but but it's not all that surprising right I mean if it's just a two-hour difference yeah exactly so we have done that experiment in mice and we don't see um difference in not only weight loss many other markers and I was telling you about this um paper where I told you that he allowed this mice to eat within two hours or 12 hours sub calories diet 2 or 12 2 or 12. yeah that's dramatic but still he did not see change in longevity even within those two so that means um when you do caloric restriction and then at least for months and you are within 12 hours window um that's that is giving the mice the best benefit the optimum benefit and um two three or five or twelve per Mouse doesn't matter at least for longevity can we conclude for humans that whether or not a feeding window is four hours six hours eight hours or 12 doesn't matter provided that calories are are similar or same well I won't go to that extent because we don't know many of this particularly we don't know how this sort of eating window will affect both success because you know we always think many of this mouse experiments even that I told you about those are done only in Mel mice but that should be changing right because the NIH I know this because I'm on study section which is just a bunch of people who record who review grants is that every Grant now has to include sex as a biological variable it's hard to get away with um or rather I should say it the way it should be said which is people are required and should want to look at these phenomena in male and female mice yes especially if there are differences so in this case um there are many I mean there is also another paper um in time history repeating that also came out a big paper showing that they um thermogenesis was accounting for loss in fat mass and time just to referred mice that was also done only in male mice um so this is um we are paying attention to it so we are now doing all of our studies in male and female and we do see big differences between male and female coming back to humans what typically happens is when you're trying to do four hours or six hours of time restricting people will inadvertently reduce their caloric intake yeah just because of gut volume I tried one meal per day and and I felt like I was eating so much at that one sitting yeah that it led to a lot of gastric distress and I got tired after the meal and part of the reason I like to do time restricted feeding is I have more energy yeah and certainly in the fasted State I feel more energized especially if I'm ingesting a little caffeine or something like that um so people will reduce um energy intake and then some people who are more active they can actually unconsciously they may be spending more energy in their physical activity and basal metabolic rate all of this combined than homozy eating and that can have a very adverse effect in long term because we know that this energy deficit and in fact there is a scientific term for that it's called red s relative energy deficit in sports energy deficit in sports okay yeah it's because nearly 40 percent of athletes um not the NFL guys but you know a lot of people who do track and field um and nearly 40 percent of athletes actually experience this Reds red S without knowing can male and female athletes both men remains Reds so it's Reds Reds relative energy relative energy deficit in sports interesting is the first I've heard this acronym we have a new acronym folks this is good to add to it a list of other acronyms but I so males and females can experience it so in females I've heard that um Reds um can lead to uh eminaria so loss of of men's of the menstrual cycle yeah so that's uh so common that uh so prevalent that in fact many women many female athletes they take it for granted that yes if they are more active then they will lose their menstrual cycle which is which may be common but it's not normal or Optimum per health and even if they don't want to get pregnant yeah yeah yeah yeah we had an expert on female hormones come on and say the very same thing that regular cycling is a is very important of ovulatory menstrual cycle is is important to try and um maintain yeah yeah so that's one but then what is really concerning is um it does affect bone health and um in this state people actually over a long period of time the loose bone mass and the bone also becomes more prone to injury micro fracture and fractures um so again it's a risk means if some people are trying to eat within very short time and they're Physically Active that happens and it also has impact on means the reason why these women are losing menstrual cycle is the hpg axis is disrupted hypothalamus pituitary gonadal axis and it starts it may start again Upstream at hypothalamus or pituitary so that means that HPA axis hypothalamus pituitary and adrenal axis may also get disrupted one of the symptoms of Reds is also depression anxiety bipolar like symptoms and we know that many um many athletes experience that we think that well this this may be just peer pressure that always trying to compete and we know that I'm unfortunately there are few authors who just can't cope it and there are many attempted suicide or suicide so this is a serious issue and there's also another new topic in the lab to come up with a mouse model of Reds and then study it but this is one risk why we should not reduce our eating interval to two such to one meal or very short time because it can have adverse side effects that we don't know now um maybe in future we'll figure out when we systematically study them there are studies that are published showing four hours and six hours time restricted eating has benefits on weight loss but those are on healthy individuals and they were in the studies so the um you know the study team took a uh well already monitoring the mature that there was no sudden weight loss or weight loss below um some safety level uh so those are very different from regular people who are who maybe even normal weight or even with uh within the healthy range if they do then they can potentially so that's why what we think is eight to ten hours maybe the ideal spot to begin with and um once you are physically active and you are also spending a lot of energy in physical activity or Sports you can even go up to 12 hours because in mice we have done that experiment um after 12 hours they do get a lot of benefits not all but so this is 12 hours of 12 hours of feeding 12 hours of fasting yeah um in humans um again nobody has done systematically 12 hours but there is one study in Europe um from tin High Colette lab and Tin high and I we collaborate so they used our my security and clock app this is a research app we developed just to this is mostly used in time restricted eating studies and he had nearly I think he started with 200 Swiss participants but then at the end he selected and took very small number of groups people who are very um meticulous about recording all their food and divided them into usual feeling whatever they wanted to eat whenever they wanted to eat and they were given the advice of Swiss nutrition advice that's given to improved health and reduce blood glucose almost like diabetes prevention program in the U.S and then the other group was given advice to eat within 12 hours this is very early on in time restorating and we thought that the mice were getting some benefit let's try with the 12 hours has any benefit the bottom line is at the end of three months and six months what he reported is both groups lost same amount of body weight and then there's not too much significant difference between groups but both groups actually improved their health so the bottom line is the Swiss nutritional advice that he was giving Which is the standard of care there it achieved the same amount of weight loss as just giving people this advice that eat within 12 hours so one way to look at it look at the result is like this and then he went to more extent and actually looked at every single meal these people consumed so they're close to I think close to 60 or 70 000 meal records and pictures he went through and then classified them to say whether these are good quality food so they call it the Nova classification one two three four one is the food that you can almost eat raw fruits vegetables um yogurt and dairy products that you can almost without any preparation and then second Nova 2 is kind of home home cooked food that most people will prepare in few minutes and then three and then fourth one is the food that you can never prepare at home so for example biscuit or cookies that we usually purchase and few other things and usually the Nova 4 are unhealthy Ultra processed food so which we should not be eating so the advice is to reduce Novak for and what I found was people who got all this advice um to improve their nutrition quality they actually improve their nutrition quality they reduce their Nova for food and people who were in time frustrating the eight within 12 hours they did not change the nutrition quality but what is interesting is they both got the same modest weight loss so that begs the question that in the maybe tin high will do this experiment again to combine nutrition advice with time restriction and maybe reduce the time to 10 hours and that might help um so 12 hours is something that I say anyone from five-year-old to 100 year old can do and if you are trying to maintain weight that might be a good way and combine that with exercise it'll be great and and people can more easily avoid Reds in that way women and for non-athletes or recreational exercises sounds like women if they distribute their calories across 12 hours are less likely to lose their menstrual cycle yeah so again this is something that we have to look carefully they have to be because we do have the my security and clock app that many people download and self-monitor and they share the data for researchers we won't provide a link to that by the way it's a great it's a great tool yeah but once in a while we do get this input from some women saying oh I started doing your Timeless routing and I I'm seeing all these problems and then I ask them okay so what else are you doing they're typically improve the nutrition quality so they're eating only salad and few and they're trying to increase the fiber intake and it's really hard to eat so much of uncooked food because cooking helps to absorb more nutrient and then at the same time they're running five miles every day and of course all of this combinedly can lead to Reds like symptom so that's why 12 I think is a good point if you're combining physical exercise and better nutrition quality because in mice also we have seen that if mice are eating healthy food and they're eating within 10 to 12 hours then they also live longer than mice that writing healthy food but Distributing that calorie over a long period of time and this is um Rafa di cabbage finding from NIH he has systematically done this study with two different types of diet and in mice and he finds the same thing that even mice that are eating within 12 hours they do live longer than mice that eat randomly even healthy food I I recall a recent study I think it was either published in cell reports or cell reports medicine forgive me for not remembering which we'll both of course cell press journals excellent journals which explored time-restricted feeding in the context of low carbohydrate or non-low carbohydrate diet so it was low carbohydrate versus low carbohydrate and time restricted yeah so these all caloric matched right between groups and then non low carbohydrate diets those are more standard uh I think it was somewhere in the neighborhood of 60 of calories from complex carbohydrates and and as I recall the um the greatest weight loss remember same calories across groups folks um was achieved with low carbohydrate plus caloric restriction yeah um and I wondered why all the popular news venues didn't cover that study um but that's why I'm bringing it up now I thought this is really interesting and um and I'm somebody who's cycled low carbohydrate diet um before I find it hard to sleep after about three or four days of being on a low starch yeah diet just personally I so I like to eat some starches yeah especially if exercising intensely or working intensely that's just a little editorial there that um but look I know many people who do just feel better on a low carbohydrate diet but what do you think of those data because it speaks to the idea that okay it's not just the total number of calories it's not just the quality of those calories it's the timing of those calories and maybe carbohydrate restriction in conjunction with time restricted feeding might be the best path for people who are looking to lose weight no I I totally agree that when it comes to nutrition quality quantity and timing all these three matter nearly 40 percent of people who maintain healthy body weight because sixty percent are overweight and rupees 40 percent of maintaining healthy body weight and out of those 40 I would say nearly majority of them are very aware about how much dieting and what quality of food they're eating so you're really an optimist you're looking at the 40 of the glass that's uh or should we say not full there was a pun intended but the um no it's a very interesting way of looking at rather than saying you know why or 60 of Americans obese uh saying why are 40 not obese that's a very interesting way to look at it yeah I mean um subconsciously we're always making the decision inside no means I'm sure that you are not going and eating um cheeseburger every day because um you want to improve yeah right no yeah exactly I wouldn't feel good yeah I enjoy a cheeseburger now and again but I um no not certainly not this stage or any stage of my life I think that um I think people actually you think the pandemic had a lot to do with this I think that people started to take a look at what they were doing to support or not support their health generally yeah I know people gained a lot of weight during the pandemic other people got really into fitness I've seen some colleagues but you've always maintained um you've always been in good shape actually the first time I've seen you in a while you've seem to have aged backwards so you are a poster uh for your own um ideas and hypotheses about time restricted feeding but but I um I noticed that during the pandemic a number of people emerged from the pandemic in better shape other people in much worse shape it seemed like it was a it was like a bimodal distribution there yeah um so yeah I get the sense that starting and stopping eating at more or less the same time each day even if caloric restriction is not the main focus yeah has additional benefits um can we talk about some of those benefits as they relate to the other things that impact health so for instance if you're starting and stopping eating at more or less the same times each day are you sleeping better are you getting more predictable uh shifts in alertness and sleepiness like can you predict when you'll feel good enough to exercise yeah maybe we could talk about that because you of course um are well known for time restricted feeding and the science around that but also other things as well um not the least of which is circadian biology generally so I always think of the main timekeepers for our system being feeding light activity and social connection did I miss maybe temp and temperature yeah yeah so how do these combine with one another and using timing that we begin and stop feeding is kind of an anchor Point can we explore that a little bit yeah so you know we got into this um beginning and end and then we you asked for the calorie how much calorie will break the fast um one thing that I want the listeners and viewers to bring back to this timing of when wait when you're breaking the fast because we equate Health with weight body weight and that's when you know we are talking about nutrition quality and quantity because both of them have impact so now let's think about mental health because a lot of people do struggle with mental health they have anxiety or depression and also um it's a gut health because there are a lot of people who also have acid reflux or heartburn and we know that acid reflux or heartburn can be exacerbated by caffeine intake in empty stomach those who have acid reflux of heartburn they're prone to that then having black coffee in the morning before any food um Can upset their stomach so that's why in those cases it's very clearly that caffeine for them becomes the trigger and that's something the food is supposed to come and then the stomach is not seeing the food so it's overreacting producing excess acid and that comes up to the esophagus and that's what they're experiencing so if people have that kind of condition then maybe they should consider when they drink their first coffee is breaking their overall fast or kind of putting them putting their health at risk for acid reflux the other thing is people who have anxiety panic attack we know that caffeine can judge you up especially on an empty stomach especially on an empty stomach so for them again caffeine can be a trigger so that's why I want to kind of differentiate that there is this mental health and other aspects of health and these are two clear examples where anxiety panic attack related to brain health or acid reflux related to our gut health in those cases when we consume that caffeine in the morning can affect so do you avoid caffeine in the morning no actually here is the interesting history about caffeine and this is something I did not know and I was once invited to this history of nighttime activity and maybe we can take a little bit of detour and talk about night time activity because that fascinates me as a circadian biologist because over the last 200 000 years means we assume that humans Homo sapiens evolved 200 000 years ago so we have been as a species we have been living on this planet for 200 000 years and only in the last you can say a couple of thousand or five thousand years when we came to control fire or maybe you can even go back to 100 000 years there is some debate um so then the question is well when you control fire and we light it up the fire and we could light up whenever we wanted we can add Fuel and we can stop the fire when we don't want it that's the key ability in humans that differentiates them from all the other spaces no other species we can always say yes there are signs of this intelligent decision making for example we know many crows can make decisions many many animals they kind of figure out strategize how to get food but controlled use of fire is something very specific to Human and when we started um controlling fire fire did not essentially extend the day because fire created a evening that is very different from what people did during the day and what people used to do during day they worked a lot means Gathering food was almost everything that we did and so in the evening after the after the after we brought food mostly tubers or maybe lentils to cook or once in a while animals so that we can we could barbecue um all of these things happen around Fire and Fire was so expensive that it was mostly communal fire so if you go back to for example Maasai and all this and such sorry populations that have no access to electricity and are still living kind of that historical life fire is a communal event and they sat around the cooked food and then what happened they did not talk about work they talked about um culture they told the sang the danced they strategize um that's how politics started philosophy started science started all of this things that are very unique to human civilization started around fireside chat so um in that way if we think about it we are still doing fireside chat the only thing is we have the microwave and the television or social media so now we chat with our thumbs right so it's still so we are hooked to that evening activity because that's when we are completely free from the pressure of the work and we want to express ourselves that's our independent kind so that's why most people find it very difficult to do time resulting and stop eating at six o'clock because it's in Grand in our in our even DNA that we want to eat and socialize in the evening so now let's fast forward and see what is the roll of coffee in this and if you look at Coffee consumption particularly Cafe where people can come and have little bit of coffee and socialize it also started as an evening activity and this is an um now we can go back to Istanbul because that's one place where Coffee Cafe is started in mid 16th century so we are talking about 15 40 to 1570 um and that's when uh I'm sorry I'm forgetting the name of historians who actually invited me and uh okay his name is I must be butchering the name but I'll try to provide the spelling and the wonderful thing about social media is somebody will tell us on YouTube the proper pronunciation so it's a great opportunity if you know the proper pronunciation please put it in the comments on YouTube I'm actually I'm even checking right now in my endnote library it's not picking up that that's right we'll provide a link yeah so what happened was um so coffee was introduced and um people came and drank coffee and talked about politics at night at night at evening and it actually started with with Sufi branch of Islam because they are the ones who uh consumed coffee in the evening and this is the branch of Islam where they actually sing and dance and all that happened in the evening so singing dancing by the stupid and then here in Istanbul people started congregating and having um talk about politics but then around the same time um some you know in Turkey there was a good sizable number of Muslims who have to do five prayers a day number of prayers at set time the first prayer is very early in the morning and then they figured out that if they wake up and immediately have coffee then they can stay awake for the first prayer and in that way they felt pretty good and they woke up I said that's how it started as a morning drink to stay awake and kind of get get on with the day but what happened was I don't know whether you have ever tried Turkish coffee it's very thick yeah a few years ago right before the pandemic 2019 I traveled to Turkey is first of all the food is amazing the coffee is indeed very very thick yeah and I have a pretty high caffeine tolerance yeah um from drinking so much coffee in yerba mate over the years and still do I really enjoy it but um yeah it's it's very intense and so what you're saying is that um coffee intake started as a way to extend into the night the ability to extend into the night at all was because of the ability to harness fire and then coffee stimulatory properties were leverage toward morning which is essentially like the way I think about it we did an episode on caffeine and some uh someone else Michael Paul and not I described it this way that you're sort of taking a loan out on your energy bank account with coffee you're suppressing the adenosine system the density makes you sleepy but that adenosine system will kick in later so you're you're it's a credit card of sorts with an interest right right and the interest being um an energetic lag that you're going to experience in the afternoon yeah but what happened was with the strong coffee um that gave heartburn and acid reflux to a lot of people so then they started eating something with coffee and that's how the culture of breakfast started in Turkey ah so coffee actually led to the development of breakfast not the other way around and that uh yeah so that's very heartening uh no again no pun intended uh for the uh the caffeine lovers Among Us uh which I count myself one of those so essentially the food before coffee became breakfast so you kind of give something to your to your stomach so it's busy digesting that and then when the coffee comes in it's not reacting to coffee and creating um acid reflux so it wasn't this fascinating so it wasn't that breakfast is necessary on its own it was essentially a buffer against the gastric distress caused by caffeine at least in that culture when in that context um we cannot say that whether the same thing happened in all over the world where coffee is not consumed but still people eat something in the morning you said you start your um first meal uh of the day at around eight what time do you wake up I wake up around six if I started to six what time do you have your first caffeine no actually I have so that's why I brought up this story because I have coffee after my breakfast fantastic I'm a big proponent of delaying caffeine intake for a few hours after waking for other reasons that my listeners have heard me talk about endlessly so I won't bother with that now but I think um allowing the suffice to say that allowing some of the natural waking up signals to occur and using light to kind of clear away and adenosine to further extend an activity is better than using a stimulant but until a few hours later this is fascinating because I've never thought about the link between extension into the night socialization or socializing rather feeding and caffeine I'd like to take a brief break and thank our sponsor inside tracker inside tracker is a personalized nutrition platform that analyzes data from your blood and DNA to help you better understand your body and help you reach your health goals I've long been a believer in getting regular blood work done for the simple reason that many of the factors that impact your immediate and long-term Health can only be analyzed from a quality blood test the problem with a lot of blood and DNA tests out there however is that you get data back about metabolic factors lipids and hormones and so forth but you don't know what to do with those data inside tracker solves that problem and makes it very easy for you to understand what sorts of nutritional behavioral maybe even supplementation based interventions you might want to take on in order to adjust the numbers of those metabolic factors hormones lipids and other things that impact your immediate and long-term Health to bring those numbers into the ranges that are appropriate and indeed optimal for you if you'd like to try inside tracker go to insidetracker.com huberman they have a special promotion right now through Pi Day March 14th where you can get 31 off their ultimate plan this is their biggest promotion of the Year again if you go to insidetracker.com huberman you can get 31 off their ultimate plan now actually I'm kind of um speaking what many other researchers have found and this this particularly this fireside chat I'm forgetting again the name of the scientist I think is from University of Washington Seattle she went to Africa and kind of recorded what people are talking of course you could not understand what they were talking Twitter and whether or not Tesla's stock is going up of course no no just just kidding folks and then came back and tried to translate and then figured out that what they're talking during daytime and in the evening were very different so um so so uh what are they talking about at night so exactly so this is like they're talking about matchmaking and talking about politics and strategizing to gather food or or even singing and dancing uh so this is um if you think if we think about it how we manage sunset to our bedtime what we do between Sunset and bedtime affects most of our health I'm going to think about that for a moment I totally agree um and by the way I'm a huge believer and and I'm in living in great hope for the idea that right now I do think that scientists understand a lot more about the different stages of sleep slow wave sleep REM sleep Etc then we do active waking States like we talk about being focused or being alert but that's not those aren't scientific terms as we know but I do believe and I've noticed a distinct difference between the first eight hours of the day in terms of cognition and we know that the catecholamines are at much higher levels plus court is also dopamine cortisol epinephrine all of that is really at much higher levels than in the later evening and so this evening time it all it's certainly in the context of mental health we know that morning and evening we are basically different creatures yeah yeah so that's why I think in the evening if you think about it um again this is uh again another set of research from um my good friend Horacio who the Iglesias yeah oh yeah yeah I'm a big fan of horacio's another he's a fellow Argentine so occasionally we riff about things related to that but he's a wonderful biologist are you guys collaborating yeah his kind of uh I say he's very humble and it's a low profile but he does amazing amazing research totally agree he does research that um we want to know but nobody is ready to do it because field research is very difficult to go to the Wilderness or go to the places where there is no electricity and then record um when these people are eating sleeping or in this case activity exposure to light that's what Horacio has done and uh it was this active watch which is kind of a modern activity tracker um but it's a little bit more refined because it also collects light information what I found was most of these Argentinian Towers who have no access to electricity they consistently go to bed somewhere between three to three and a half hours after Sunset so this is very important because we always think that um our ancestors when they didn't have electricity as soon as the sun went down they just went to sleep no the fire extended the evening so they were staying awake for three to four hours kind of um you know decompressing themselves that we say and then doing all these activities cooking sharing meals and then they would go to sleep and if you look at the slip onset variability it was very small like they're going to bed almost within 15 to 30 minutes standard deviation so no night owls versus morning people exactly so we'll get to that none of this this uh I get attacked by for many reasons it just goes with the business I'm in of being public facing these days but every time I talk about viewing sunrise or low angle sunlight you know getting some sunlight earlier someone says well I'm a night owl and they just it's almost like a a protest of trying to protect identity it's become this ideological I I identity related thing I'm a night owl I'm a morning person and I'm not but you're telling me that in these cultures where there is intellectricity but there is fire people are going to sleep within all of them within about 15 minutes of one another yeah so there is no such thing as a night owl or a morning person in the context I still actually I asked him pointedly because uh uh and then he said no he has not sinned and says dragged hundreds of people and if we ask there are many many sleep researchers or at least the public facing sleep Physicians or experts they will say yeah we can say one third of people a night hour one third of morning and then one third are in between but yeah they call them like Bears wolves and you know and I'm not being disparaging of that idea I think people really do feel as it as if they Orient towards one pattern or another when I was an undergrad student I never went to bed before midnight and actually midnight was my going to bedtime exactly like 11 45 I'll try to get ready to hit build and then by 12 I'm in bed and I used to get up at six six fifteen that's a pretty short sleep with an alarm of course and but then day time I used to take 45 minutes to one hour nap and that was regular like even if uh whenever I got time of course in college you know you don't have the whole debt unlike in high school you don't have opportunity to nap but in college you can I might have been one of those kids with this hoodie on napping on the desk but they come around and they wake you up yeah but in this case just come back to the dorm and um after lunch usually I used to take a nap so um then in grad school I remember I rarely went to bed before 2 am and I could have clearly said that I'm a night owl and actually I was a night owl it was very comfortable staying up so late I was very productive doing experiments writing all this um manuscripts mostly and but then afterwards when I looked back in postdoc when I had when we had our daughter um then things started changing because you have to put the baby to sleep and then after the baby sleeps it's almost when you have a baby your life revolves around the baby so then we have to dim down the light there is no caffeine and alcohol drinking or any other things after the baby sleeps because we cannot do too much noise and others so then I realized that no I'm actually not a night owl and I became kind of more normal because I could go to sleep between 10 and 11. and um that's how I thought well maybe this was very unique to me but what is interesting is I have another colleague good friend Ken Wright Jr Colorado at Colorado and he also had grad students and um and postdocs like me who strongly believed that there were night owls um just like everybody else and he took Ken took the whole Lab for camping and when they were camping of course there is less light and a lot of physical activity hiking during the day and they all went to bed between 9 and 10 30 p.m I love that study yeah what Sachin just described was a study I think there were two studies uh there were two yeah and um what's interesting as I recall is that after going camping for a weekend where people awake with this more or less with the sunrise yeah and go to sleep a few hours after Sunset yeah their melatonin rhythms and cortisol rhythms and sleep wake rhythms persisted on that schedule for several weeks despite returning to environments where there was a lot of artificial lighting which I find amazing that just a weekend of consistent rising and um going to bed with the sunrise and sunset yeah more or less allowed a reset that was very long lasting yeah so um actually even in Horatio study he found that almost all the tobas they wake up around sunrise time and it's amazing when I look at the standard deviation it's like so tight so take that night owl so-called night owls I also in graduate school I would work until 2 A.M I loved it I'd blast music in the lab everyone was at home pretty much not everyone but there were the the night crew and then I'd get in sometime around get up or sometime around 9 30 10 and then get in around 11 and it was no problem because I was going to stay so very late and then over time I noticed I've become more locked to a standard schedule so I think what we're saying is that the clock can our internal clocks can shift yeah but this idea that we are genetically biased towards one schedule or another may need revisiting that's what that's the conclusion I'm taking from this a couple of aspects one is um you know some people are genetically so pre-programmed because the other flip side is what is called technically familial Urban sleep Fest syndrome so these people um you can give them caffeine or whatever but they will fall asleep say at eight o'clock they cannot stay awake till nine or ten and since it's a very strong phenotype in sleep and circadian rhythm field they are very well studied so in fact Louis potashek and ingwifu they were the first one to track one family like this and then they figured out there was a mutation in one of the clock genes period two that clocked in and that mutation um allowed the clock to run in a way that these people went to bed very early I guess historically given these Fireside Chats those people were probably not contributing much to their political discussion whatever that was decided after they went to sleep is what they woke up into that reminds me because as you were describing the difference between nighttime discussions versus morning discussions is there any theme to what is discussed in the morning versus in the nighttime where people just sipping their eating and sipping their caffeine and just waking up um but is there are there any ideas about what morning discussions really consistent morning discussions or daytime discussions are mostly about um work and like hunting Gathering or farming all that stuff and even these days that's what we do we you know you go to I go to work and it's mostly one meeting after another and we're talking about how means if you're in different communities and we're solving problems or your students come with questions you have your TA or the office hours all these things work related we're not talking I mean serious philosophy of unless you are in a philosophy department and you are talking about political science and also we are not singing and dancing so that's why the evening activity even these days are very different and typically the evening activities uh where we express ourselves we express who we are we feel like we are free and um you know you and I we have this academic intellectual Freedom we can talk about our work just like we are talking now there are a lot of people who work for even in tech industry they may be working for Google and all these big tech companies they cannot talk about their work to anybody else it's all secret it's all secret so just imagine that staying so they're spending more than half of the wake-up time at work thinking and doing work but they cannot talk about that work even sometimes to their own family members so then what happens for them a lot of people also do the same thing like um the person who is going and baking in a restaurant or cooking or the person who is taking trust and driving or nurses and doctors can't talk about their patients reality yeah yeah and some people just don't want to talk about it it's so stressful they don't want to bring that stress home so that's why I always say that from Sunset until we go to bed during that time we try to find time for ourselves people say this is me time the me time is essentially we want to truly Express who we are or we want to entertain ourselves because on the Fireside chart it's not that everybody was a performer there are also some audience so we always switch our roles sometimes we are performing and sometimes we are observing so that's what happens with me time I love this so um maybe social media time should be restricted to just maybe a small portion of that evening time because I would hope that people would also interact socially within in the room maybe in a constructive way or maybe you use that for connect with your family members whom you love or you can have some productive discussion or something so it's it's kind of interesting I think it's extremely interesting because I think again this this conversation about time restricted feeding is really conversation about circadian rhythm and sleep wake activity and human evolution right um so that's why let's go back to this um uh Night Owl because uh we we kind of made a comment that maybe it's not genetic but this is where I'm still wrapping my head around because you know these days there's some J-1 studies where they're trying to look at night owls to see whether there are some genetic Lincolns and you know sometimes we always think yeah if you take half a million people of course you'll find some low side but going back to this idea that are some people more sensitive to light so that it's likely that the same level of light even in the same household may make some people stay awake late into the night whereas other people are more resistant to light so that they can go to bed early and since light has become so prevalent these days and this tobus story that we are talking about or people going on camping that is we have removed that light um so there is some um evidence that People's Light sensitivity particularly the iprgc or this intrinsically photosensitive retinal ganglion cell or the simple speakers the blue light sensors in our eyes um there seems to be even one log unit change in sensitivity as measured by pupil constriction so for some people a small amount of artificial light at night could really shift their circadian clock yeah wake them up essentially and then for some it manner yeah I'm very sensitive to light at night yeah exquisitely sensitive to it oh so then you are like a teenager yes in many ways um I've been told this thank you um yeah I think um I have actually switched to using a red night light but I should be clear not a fancy high cost red light for sake of any kind of infrared simulation but a red party light type light and I find that was based on reading one study that we covered in an episode on jet lag and shift work which was that it seems to reduce the cortisol releasing properties of light at night to use redshifted light yeah so I just use a red light bulb I actually travel with one if I go to an Airbnb or a hotel and I switch to red light and I find that I fall asleep and stay asleep throughout the night much more consistently especially in when I'm in New environments which always makes it disruptive to sleep um it's made an enormous difference in the depth and duration of my sleep and um because oftentimes Hotel lights you know in the bathroom you'll turn them on you're just you're just getting beam and you're right some people don't seem to to be bothered by that I I really struggle with that yeah and in fact in Tina's uh right after puberty um there seems to be a I think that's when the teenagers become more sensitive sensitive to light uh and it's very it's well known that the teenage boys and girls they tend to stay awake late into the night and they can stay up to 12 mid past midnight although they can stay of that lid that doesn't mean that their sleep schedule is reduced their body still needs the same amount of sleep as other teenagers so that's why they are more likely not to wake up at 6 30 or 7 when we expect them to wake up and go to school um I have a question and I ask every circadian related biologists that can come into contact with this and no one has been able to give me an answer one way or the other but I grew up hearing that every hour of sleep before midnight was of more value or potency than the hours after midnight and indeed I find that if I go to sleep at 9 30 or 10 P.M I can wake up at three or four a.m feeling pretty fantastic and ready to lean into the day but if I get the equivalent number of hours of sleep starting at midnight I feel like complete garbage when I wake up after five six hours so um is there any truth to the idea that going to sleep Within three hours of sunset is somehow better for our circadian timing mechanisms well um there are a few things one you said that you are very sensitive to light so I assume that you also avoid bright light in the evening as best I can yeah as best as you could can and then what is happening is with a sense of that bright light your melatonin levels begin to rise so you are prepared for Sleep um of course this is something that we cannot measure because measuring melatonin in every one hour or 30 minutes um is very difficult and there is no consumer fishing product yet so it's likely that your your body is preparing very well under this dim light to fall asleep and when he was trying to stay awake and go sleep at midnight then maybe from Midnight for the first three or four hours you are sleeping well but then after that your melatonin level might be beginning to fall and it's not only melatonin in your core body temperature and then your heart rate and everything is changing to make you awake but the Sleep debt that you have accumulated is pushing you to be in bed so there is this tension between the Circadian aspect and your sleep depth and unfortunately you cannot have good night of restorative sleep for the second half of the sleep because of the tension that makes good sense yeah so that's why um you know you are not the only one means there are many people who who experience that and in fact a lot of people think that well this may be the way I sleep maybe I'm not um I am not designed to sleep restoratively until you know I sleep one day just like the camping trip and then they realize what it feels like what you're missing yeah absolutely um I want to make sure that we talk about the other aspect of fire which is uh you had a paper that came out recently very interesting paper studying firefighters and time restricted feeding and firefighters would you share with us the the general contour and maybe even some of the specifics of that study because I think it's very interesting for for sake of shift workers but for everybody really to understand these results yeah so let's go back to shift workers because um this also relates to all of us because I always say that each of us is a shipped worker or has lived the life of a shift worker um and we have experienced how terrible difficult it is um and now let's start with what is the definition of a shift worker or um shipped work like lifestyle there is no Universal definition unfortunately but there are many European countries and particularly if you go to International level organization um then you'll find some references different European countries have slightly different definition which essentially points to if you stay awake for two or more hours during your habitual sleep time and when they say habitual sleep time they assume that we are just like you said we are kind of programmed to slave somewhere between say 10 pm and then stay in bed and kind of wake up after 5am so the idea is if you stay if you're staying awake for two or more hours between 10 pm and 5 am and you are engaged in some activity whether it's physical activity or intellectual activity you are not lying in bed and wondering worrying about something but actually working so that defines that's defined as shift work and you don't have to do it every single day even if you do it once a week for 50 weeks then that itself is enough to disrupt your physiology and Metabolism Behavior brain function like a shift worker the reason is as you discussed when you change our external timing queue so in this case when you travel jet lag or or traveling across three days three hours of jet lag will take three days to reset similarly if you're staying awake for two hours extra or if you're waking up two hours before your habitual wake-up time then we just don't get wake up and then be engaged in some activity in the dark most of us unmends unless you are wearing a infrared goggles we turn on light and light resets our clock so in that way every time we stay up for two or more hours even for one night then for the next two nights our clock is kind of trying to catch up so in that way for three days the day of the disruption and then two days following the disruption um a clock is trying to catch up with the outside time so clock our body is not on time without clock so that means almost for half of the week or half of the Year our clock is trying to catch up so that's the definition of shift work so now let's come back to Department of Labor Statistics um U.S government um they have not been tracking what percentage of people are doing shift work accurately because there are many difficulties in tracking too but it's generally accepted that one in five working adults is a card carrying shift worker card carrying shift workers means they are nurses doctors firefighters um and Bakers um truck drivers and many in the service industry so that's one in five so twenty percent of working adults then if we think about all the college students just like I was doing and you must have done um they're also deadlines grants granted lines then we are also experiencing experiencing the lifestyle of a shift worker because we are delaying sleep even if you're delaying sleep by two hours for most of the college students for five days and then the weekend you are trying to catch up that's kind of a security and disruption going on then you take 1.5 or 1.6 million new months um in the US every year so when the child is born and that mother is a shift worker and actually that mother is worse than a shift worker because um you know you don't know what time of the night the baby will wake up and how many times and there is no weekend in motherhood so they're also living the life of a ship worker um we don't count many food delivery and Uber drivers Lyft drivers are shift workers but they many of them we know that they live so in that way we think the actual number of people who are experiencing the life of a shift worker is somewhere around 50 percent of the adults population at any given time so that's why it's also another point that you might have heard from people that will say oh I cannot do time restricting because my schedule is messed up or I work in a different way and um that comes into play so that's why we thought um okay so we should try something on shift worker another point is although one in five people are shipped workers they carry disproportionately heavier burden of disease because almost all age-related disease that we can think of whether it's high blood pressure usually high blood pressure starts in 40s or 50s high cholesterol um gastrointestinal problem in digestion um chronic inflammation of the colon and then even colon cancer in many cases and then of course diabetes all of these are disproportionately more prevalent among ship workers but then when you think about clinical trials whether it's a drug or a lifestyle often one of the top 10 exclusion Factor criteria is shift work so people who are doing shift work we exclude them from many of these trials one thing is most Physicians and most scientists even people who do shift work they know that they are their body and mind is so messed up that often time even medications may not help them and so that's why we don't try new medication why to take the risk when we know it may not help them and then when it comes to Lifestyle intervention whether it's sleep extension for example we cannot do because they are supposed to stay awake and do their job we cannot ask them to stay asleep at night and then physical activity and exercise some people can do but some people are so tired after all night that they don't have the energy to do physical activity and then nutrition again most nutrition studies involved the participants to come to the clinic and get um one-on-one or one or attend group sessions and they cannot come and they cannot even sometimes come to the clinic visit um when people have to take draw blood and in fact there is another caveat that just if suppose I am healthy perfectly normal blood pressure blood glucose cholesterol everything is normal and I live the life of a shift worker just for five nights that means I'm sleeping less maybe four or five hours and even if I don't eat at night time of course many shift workers also feel hungry and just for um to keep their work they eat um just after five days my blood glucose level will read almost like I'm pre-diabetic wow I actually saw a study in publishing procedures in the National Academy that showed that even a hundred Lux dim Light present in the room while people are sleeping with eyes closed can lead to disruptions in morning uh blood glucose levels in directions that are not good yeah um one night so the the faint clock in the corner or even a a night light that's too bright yeah could be problematic um by the way folks these effects are reversible so I whenever I say these things I we get a lot of comments about oh my goodness what have I been doing for years but you know kids with Night Lights this is an issue yeah um but what I'm hearing is that one in five people are truly shift workers in the classic sense their jobs require they work at night or into the night and sleep into the day but far more people are shift workers by virtue of the fact that they're Tweeting or working or watching movies at night even though it's not work in that they're not being paid for that time they are essentially operating like shift workers if we add those two groups together would we say it's what uh a third of Americans I would say half of America half of America yeah if you take teenagers because you know high school students and college students because again going back to horacio's uh study because Horatio also collected activity data from high school students and college students and we have replicated that with high school students and college students in San Diego so that's Seattle and San Diego and this study now there are many sleep researchers that have been collecting this data and what we find is um typically the high school students they are going to beds around midnight and college students at least the UCSD students we found maybe one out of 100 who went to bed before midnight that um reminds me that Horacio Iglesias just published this really nice paper um showing that counter to what we believe students now this is the University of Washington in Seattle I should mention where it's very dark in the winter young people see other people in their 20s are staying up later in the winter months compared to the summer months yeah which is you know totally counter-intuitive you think everyone stays up late in the summer and goes to bed early in the winter but because of artificial lighting it's the exact opposite yeah so and another um it's um I don't know whether Horacio monitored it but my other suspicion I'm not saying whether it's true in Winter we are more likely to consume more coffee hot chocolate in the evening and that might also be delaying slip onset that makes sense so in that way again here is another thing which can be related to policy or practice at Educational Institute so what happened during uh kovid was everybody went to remote learning um the assignments became digital and assignments submission became digital and there are many systems online systems that came into play and by default the assignment submission deadline became midnight so then now what is happening is I don't know about Stanford in maybe when you are giving assignment um one is the deadline in line typically midnight yeah so then most of us most students they will try to cram as much as possible try to solve as much as possible and submit at midnight and it'll be really cool to go back to your system administrator to see is there so many frequency plot of frequency distribution of what time people are submitting the um assignment because we know means when we submit our grant yeah so I mean you know you hear about the Obesity crisis the crisis of metabolic disorders not just in the US but everywhere in the world I mean it's really striking I remember going to a keystone meeting scientific meeting in the early 2000s and there was a map of the United States and it showed where the Obesity rates were over 30 percent in adults and the entire country basically was lighting up like crazy now it would be the entire country but there were these kind of zones in the middle um that were almost devoid of of uh obesity Colorado namely Idaho at that time those are now also Fallen Under the Umbrella of rampant obesity and you and everyone is speculating okay is it uh you know is it seed oils is it um is it this is it that is it highly processed foods I'm guessing it's all of those things including lack of activity but one has to wonder given everything we're talking about in terms of metabolic dysfunction late shifted eating all these issues with late shifted eating and staying up late with artificial lighting whether or not that could be one of the major factors in the so-called obesity crisis it's likely you know we always say Freshman 15 that's right because this is a gaining 15 pounds in their freshman year in college and um this is where I think as executor professors um it'll be interesting to go back and see what can we do because another thing that's also becoming more and more common for example I I give a security under the class means I just give two lectures and I remember when I started 15 17 years ago that lecture used to be around 1 30 p.m or 2 p.m in the afternoon and it's a two and a half hour lecture so it's done by five and for the last um before the pandemic I realized that they changed the timing now the lecture was starting at 7 pm so I was finishing by 9 9 30 pm and these kids they had to go and eat after 9 30. studies socialize find aside chat fireside chat and then to express themselves like to feel free from assignments what are they going to do that after they submit the assignment then they're going to do that so that's why we have to go back and revisit this issue say okay so for adults for most of us who are working a day job our deadline is 5 PM in most cases right men's at least an University system the person who is submitting the grant or who is doing taking care of my IRB or I cook they are all living at five o'clock so for me everything has to end by five I think for most people out there so this the race is a kind of macroscopic question which is maybe it's not so much about restricting the feeding window but maybe it's about feeding mostly in and being active mostly in the early part of the day I mean you know I could imagine a Time three four years from now when it's about when waking up early and going to bed within three hours of sunset is the protocol which harnesses all other protocols right you're going to exercise you're going to do it in that time you're going to eat you're going to do it in that time you're going to socialize you're going to do it in that time and in doing so you're also avoiding a lot of the issues related to disrupted sleep so that's why all these things I just said Timeless repeating is just one aspect of the security and health and these are all interconnected and going back to the comment about um within three hours of sunset yes um that's good but then what happens in say Toronto or Vancouver in winter time I guess they're going to bed very very early but also waking up very very early yeah you know one of the things that I hear all the time because I'm always beating on the drum of getting morning sunlight even if through Cloud covers people say there's no sun here this time of year and I I forgive me but there is Sun unless you live in a cave their son is just coming through cloud cover no matter where you live in the world their son yeah unless you live in a cave of course so um I want to make sure that uh we didn't Overlook what was the major conclusion of the firefighters so the reason why we did this study was as I said there are a lot of us who are living the lifestyle of firefighters or shipped workers and shipped workers are excluded from studies so that means whatever we are learning about a lifestyle or even medications that may be beneficial for people who actually have a normal schedule um but not for people who have a disrupted schedule and if you look up um clinicaltrial.gov there are more than 400 000 studies listed and if you search how many studies are on shift workers it's less than a thousand and then if you ask most of them are to see what is wrong with shipped workers like that's how we know that shift work increases our risk for metabolic disease cancer and even some aspects of dementia but if you ask how many studies are done to improve the health of shift work alone and that's less than 50 means I mean so I have to go back and check the actual number but it's less than 50. wow so that's why um we got super excited we thought um from circadian rhythm perspective that's something to address so this study again this kind of study is only possible because I'm at Salk and we are affiliated with UCSD and um I can work with UCSD Physicians to do this study so I collaborate with Dr Pam tobb who is the director of cardiac rehab center in UCSD and Pam has many firefighters as her patients and we both know that the number one cause for death and disability on work for firefighters is not fighting fire but just getting heart attack and stroke uh so they have a very high incidence of heart attack and stroke and they're also highly prone to different kinds of cancer and it may be difficult to ascribe cancer to disruption security and disruption because they're also exposed to a lot of toxins anytime Fire Burns that smell of fire is essentially smell of carcinogens and they're breathing even if they have the um hood on and respirator they're still good so the idea was very simple we know that firefighters nearly 70 percent of firefighters in the U.S full-time firefighters because there are volunteer firefighters and then full-time firefighters the full-time firefighters 70 of them work 24 hours shift so for example in San Diego they come in at their shift is from 8 AM to 8 am the next day and they do at least in San Diego they do one day on one day off on off four cycles and then four days off and but in some fire departments they actually do 48-hour shift so they come for two days two days off two days two days off and then four or five days thank you firefighters yeah I mean um so then the idea was okay so we'll screen firefighters and then find firefighters who are metabolically unhealthy and then we'll see whether they can actually follow 10 hours time restricted eating because the point is if firefighters can follow it then everybody else will pay for us with all that stress if they can and this is again where I should also acknowledge the San Diego fire and rescue Department because without their health we could not have even submitted the grant and at that time David picon who is the health and wellness battalion chief he's the one who actually approached us um because he is very careful he knew that the job that they do makes them weaker and long term and can kill them in long term so he was always looking for new Solutions so he approached us and then we said this is the idea he said well I love this idea because we are not asking them to sleep more or we are not going to cut down their over time or shift or change the work schedule the only thing we'll be doing is ask them to eat within 10 hours and hopefully we can do this so consistently between the days that they're working and not working yes so that means if they're from 8 A.M to 8 A.M working then the next day then they go home then they're going to eat on the same schedule they did when they were at the fire Firehouse yeah but while at home so they're not allowing themselves to to deviate from that yeah so we we thought whether they can do it or not because the number one goal or the primary outcome in this clinical trial was feasibility can they do it and then second was if they do it then what happens to their blood sugar and weight and all this other stuff and then we started the study and we hit the next hurdle and that is um you know firefighters are very very tight-knit community and they want to make sure that you understand their culture and the best way to understand their culture is to live the life of a firefighter so Emily Manoogian who is the first author see and then we had Adina jadurian who is now in med school she was a research coordinator at that time they volunteered they said okay we'll go to the busiest fire station in San Diego and will live the life of a firefighter and the San Diego fire and rescue and the city they all agreed they reported for duty at 7 30 in the morning they were assigned a bed in the station because all fire stations do have some beds for firefighters to rest and they have a sign bed so they've assigned a bet um yeah so every time a 911 call chem and if that fire station in that fire station that fire engine was called then just like other firefighters they had to run get into the gears just issues and um a jacket and a helmet and getting the seat and attend the call of course they won't go to this side they just get out of the truck wait there then come back so in that 24 hours MLA got 10 calls at night that she had to run to but there are more than 10 times the um they got the nine one every time the 911 call came then there is a bit that goes out all firefighters were sleeping or resting they would get up or if they're doing something they'll look up to see which engine is called and interesting so it's not just the ones that go out it's everyone gets woken up everyone gets woken up so that means in a night typical night they're waking up um 10 15 20 times sometimes so they're almost like um you know new months are like firefighters because they don't have any idea what time the baby will cry and for what reason also they don't know so similarly it's five so that's what Emily did and then next morning once you came back she was like no it's practical seem easy yeah so so then we did the study and we essentially assigned uh all the firefighters we recruited 155 Fighters we assigned half of them to Mediterranean diet because you cannot do any harm you have to give them something good so that's another thing they said no we want something that we know works for firefighters and there was a Mediterranean diet study so everybody was supposed to follow Mediterranean diet and then have nearly 75 of them were supposed to eat within 10 hours we did not fix the 10 hours because we said um you pick your own 10 hours that you can stick to but it has to be consistent from day to day so if you start eating at 9am you finish it not at uh you know at seven PM pm and then try to be yeah okay try to try to be consistent because we said yes we understand that there will be some things and you can take maybe half an hour here and there and we'll see how many times you can do it and um what is interesting about although they were all doing 24 hour shift more or less chose to begin eating somewhere between 8 AM and 11 am and they did not skip any meal they had their first meal or what we call breakfast but it was several hours after waking up because they are waking up at five or six and the driving to come to work at 7 30 or 8 and they're eating the first meal say between 8 and 11. and then the finished meal 10 hours later and what we found is more or less most of them could stick to doing this at least five days out of seven days um and then at the end of the study when we look at their health parameters one thing as I said we recruited everybody who can so that means nearly one in three firefighters were completely healthy they had no sign of any um any illness no high blood pressure high blood sugar or high cholesterol depression or anything so since we have one third of the population who are already healthy and then everybody has slightly different conditions some have high blood pressure but they don't have high blood glucose somebody has high blood glucose but not high blood pressure so it was kind of heterogeneous so we did not see big difference in weight loss or any wet change between these two groups another thing is firefighters actually run almost eight to nine miles when they're at the job because that's part of their exercise routine but then one thing that changed significantly in the time restorating group was what we call bldl particle size and particle number because this is something that we know this very low density lipoprotein these are atherogenic and if we can manage them much better and we reduce the risk for atherosclerosis so that's one parameter that changed in the time restricting group even when you combine all healthy unhealthy everybody now if we take firefighters who are beginning with high blood pressure then we saw a significant reduction in that systolic as well as diastolic blood pressure and the change in blood pressure of course we don't claim that in the manuscript but when we talk about it some physician would get up and say wow that looks like almost there on a blood pressure lowering drug so the extent of blood pressure lowering is equivalent to somebody taking a antihypertensive drug amazing yeah and then those who started with high blood sugar of course we didn't have too many type 2 diabetic but there were a few few pre-diabetic and they could better manage their blood glucose and this is interesting because once shift workers become pre-diabetic or diabetic they have more difficulty managing their blood sugar than non-shipped workers because the work schedule itself will mess them up too much even if they're on many medications they have difficulty that's fascinating and I I'm really glad that you explained the study in such detail because I would have thought you know from reading the abstract and I did look at the data but if someone were to look at the abstract they'd say oh firefighters so they're waking up in the middle of the night and they're you know throwing on their gear and going out to calls and doing but if I understand correctly all firefighters are being woken up by the signal which makes the firefighter population a bit more similar to the more standard population who's waking up in the middle of the night to use the bathroom getting on social media for a couple of minutes or flipping on the lights I mean it's maybe not as severe as what firefighters are doing um but we know there are blood sugar regulation issues related to those multiple middle of the night wakings especially if people are then staring at screens yeah um so I think it's really important that people were able to hear about the the deeper Contours of the study uh I mean this result of regulating blood sugar better is really powerful I get asked all the time you know I've got a new kid or I'm a shift worker how can I do this morning sunlight viewing um what I'm hearing is that keeping a regular meal schedule every day at least five five out of seven or as close to every day it's sort of like sleep I always say try and get a really great night's sleep 80 or more of the nights of your life and on the other 20 hopefully it's for fun reasons a great party or something like that or a celebration of some sort um that seems to me a great Anchor Point when one can't reliably control their sleep wake cycle does that mean that if somebody is coming off of shift work and they're very very tired that they would be better off staying awake and eating than sleeping well it's uh yeah so this is where we get into nuances so here the firefighters are 24-hour shipped workers so that means and they have been working this shift for a very long time so they have figured out and one thing is yes firefighters are different from nurses and healthcare workers who have to work throughout the night and they're staying awake throughout the night whereas firefighters they get opportunity to sleep then even with their pen calls they actually have opportunity to come back and go to sleep and in fact when Emily and Adina they were in the fastest and what they observed was firefighters after they after attending a call they are not coming back and playing cards or trying to watch the news or get the score they know they will just go back and lie in the bed and switch off the light so whenever they got any opportunity to sleep they would try to sleep so in that way their sleep debt and sleep pressure during day time is not as strong as a night shift nurse or a truck driver who is driving all night because they have they're staying awake throughout the night so when people say yes you found this and can you extend it to other shift workers my answer is no we have to go back and figure out that's why we went to this station and figured out what would work for them if I have to go and do this for some nurses maybe even I will go or our staff will go and figure out what is the work schedule what happens do they have opportunity to eat do they have opportunity to even take five minutes break what do they do during break and all of these things come into play but here another thing is um I always said that in other time receipt reading paper we see change in nutrition quality and quantity but here we also saw that somehow both groups inadvertently the improve the nutrition quality because everybody was told to eat Mediterranean diet they increase their fruits and vegetables and olive oil and text slightly and when they had to stop eating early they also reduced the alcohol intake and this is very significant because many shift workers just to cope with the shift work that tend to depend on alcohol at night and caffeine in the morning so they begin their day with caffeine and end with alcohol and now we can relate that many normal people who are not doing shift work we also more or less begin our day with caffeine and many of us and with alcohol and then when they reduce that 18 to 10 hours and then we saw a significant reduction in alcohol intake in the time restrating group but not in the standard of care or Mediterranean diet group I certainly support that we did an episode on alcohol and I was shocked when I researched that to learn that zero to two drinks per week is essentially the threshold Beyond which you start seeing health deficits in particular Cancers and metabolic disruption sleep disruption and increased anxiety when people aren't under the influence of alcohol I mean it's a pretty incredible how alcohol has kind of escaped as the the opposite of caffeine and therefore um not a health hazard it's and here I'm somebody I have a drink every once in a while no big deal for me I can have it or not have it but it's just striking how um alcohol despite extensive data that it can really disrupt Health even at three drinks per week yeah is um is just avidly consumed as if it was kind of like food or caffeine it's really incredible um I I want to make sure that I Circle back to something you mentioned earlier because I know they're going to be a number of people that asked this if I recall you said that provided that the feeding window is not shorter than eight hours that men women and children can use time restricted feeding um yeah so what I say is um 12 hours 12 excuse me 12 hours thank you for that clarifying um because we did a study that was published in 2015 and again um behind many of our studies there is a story so we are publishing all these Mouse stories and then I would go to conferences and and of course the um some some people would give me a look saying well you must be doing something wrong we this just breaks the X law of thermodynamics because how come they're eating the same number of calories and not getting wet and of course by that time we figured out that at least in Mouse Timeless repeating also changes the gut microbiome in a way that the mice may be popping out a little bit more fat than sugar than absorbing them so one thing that happens in time restricting at least in mice is the liver cholesterol metabolism to bile acid and bile acids excretion in the gut changes because they gut microbiome changes so this is a very nice study when Amir jarinpar was in the lab now he has his own lab in UCSD and he meticulously did that and we we even did bomb calorimetry from the poop and metabolomics from the poop and then we figured out that they excrete some some calories and then that brown fat activity goes up so there may be burning some of these extra calories so they're more thermogenic more thermogenic but anyway so you know one nice thing awesome thing about Salk is if they say that your science is going well then they will find ways to help you and this is terrific yeah and um this is when Bill Brody was our president he was the president of um um Hopkins for 12 years and then he was president and um that time he had started this Innovation grant program which was funded by arvind Jacob uh Arun is the founder of Qualcomm it was also a faculty at UCSD so he understand there are very few Tech leaders who actually spent some time in Academia so he understood the pain of getting grant money when you have some interesting idea or test some ideas so yeah no knock on the NIH but I'll do it anyway because I sit on study section for the NIH I mean NIH wants to see proposals for things that are so certain to work that they're mostly done and so really groundbreaking work can happen and does happen with NIH funding but more often than not is it is the generosity of philanthropists like Irwin Jacobs and other people that allow the really pioneering um the new stuff the cool stuff yeah the groundbreaking stuff the stuff that really no I'm not gonna say really matters it all matters it's all important no it matters but uh you know it's high risk and um NIH when San is is not just government is not making money from thin air means it's taxpayers money so there is a little bit responsibility or conservative that okay so we should not waste tracks first money on buying this guy we're not talking about politically conservative we're talking about um scientifically conservative to be so careful what language nowadays pretty soon we're just gonna sit and stare at one another at the microphones to stay safe um so so that's interesting so they so that's why I started this and then what we did was we um I had an awesome grad student and we got this funding from Arwin and also there are some any philanthropy matters so actually the way we say is yes if you give me 50 bucks then that 50 bucks towards goes towards buying the gloves and a friend of tubes for one postdoc for maybe seven days so it's so true I think a lot of people don't realize that 99 of laboratory scientists just they they don't make any money off their discoveries and even if there is a patentable discovery typically the The Divide between the institution and the company that will eventually put that to Market is so slim in favor of the the others involved that you know scientists really do this as a work of passion labor labor of love so so we we came up with this app my security and clock at that time and we took some um you know lessons from Tech leaders um particularly from Amazon one click checkout um because we thought most nutrition apps actually ask people to detailed describe or they add go to their food library and then person size they said okay so we'll just shortcut all of that I just ask people to take a picture of the food open the app one click take a picture second click and press save third click and when they said the picture actually came to our server did not stay on their phone and we asked 156 people who are not shipped workers just regular worker or Homemakers to be part of the study no student was allowed to be part of the study because we know that there's a lifestyle is like ship workers and we monitor for three weeks and so here is some nuances and I want people to understand when somebody is starting to eat at say 7 A.M and since the recording everything we've we've got every single thing even if they ate half a cookie they had to take a picture and they actually took picture because it's not it becomes second nature after three or four days that every time they add something even if there is a glass of water they actually take a picture because we asked them take picture of everything we'll figure out what it is what is surprising what we found the median uh so the median number of times people eat within a day 24 hours a day is actually seven so it's not it's not that we are eating three times a day we actually snack a little bit seven times per day seven times and there are 10 percent of people the top decile was eating 12 times a day wow um and it makes sense in retrospect sometimes maybe I'll fall into that seven or eight before um I did this study because you know getting up having coffee with cream and sugar is one and then I ate my breakfast that's two then I came to the love and I found that cookie that's three I went to a meeting and there was some cookie and something else that's another one and lunch and then afternoon somebody asked me to go out and have a meeting and so if you think about it it's very normal that we can go seven to eight times ten times but then if we look at what time say I start breakfast and as I said and we see that in many people they'll start at seven o'clock Monday then 7 30 another day then 8 15 another day or they go back to 6 a.m because they had to get up early and go to work so we took all this food data from three weeks and then asked what is the time when your body's system is expecting it to eat because it's kind of averages Southeast kind of thinking okay maybe for you if you're eating breakfast at say somewhere between 6 AM 7 30 7 45 I eat it maybe you are expecting food around seven o'clock let's forget about 6 15 that's an outlier and then similarly at the end of the day if somebody is eating finishing the last bite or the night Gap whatever you call it say one day at 9 pm 9 30 p.m 10 11 12 30 or 1. Let's ignore that 1 and 12 30 but still we got somewhere between seven to eleven thirty for that person over three weeks time so this is how we kind of figure out what is the likelihood that your body will encounter food so when we do that what we found was nearly 50 percent of our dogs in our study ate for 14 hours 45 minutes that window when your body is expecting food so it's easy to say that 50 of adults are eating within 15 hours or longer wow and and quite frequently throughout quite frequently too and then if we ask what fraction of our adults were actually eating the conventional within 12 hours three meals a day or something like that it was 10 percent so this snacking has gone up dramatically however you wanted to find snacking the frequency of food intake throughout the day and outside this breakfast lunch and dinner there are all these small snacks here and there and also for a lot of people the dinner is delayed and we went back and looked at okay so what kind of food people are eating late at night and all that stuff and what came out interesting which is very counterintuitive is people who prepare their own dinner they're more likely to eat later at night because they're coming home and then they're taking some time to prepare dinner and then they're sitting down and eating or maybe they're eating next to the computer whatever it is so it's kind of interesting that came out um but coming back to your point that's why I say that nearly 90 percent of adults are eating for more than 12 hours so that means a lot of people can there is scope or there is enough head space to reduce and eat within so as I said all of this are interrelated so when you think about children most sleep researchers agree that children and teenagers should sleep somewhere between 9 to 10 or 11 hours because young children even five to ten year old they should sleep nine to ten hours they're just pumping out growth hormone and growing growing and then the teenagers actually the recommendation is and they should be sleeping nine hours because if you take teenagers take out all the stimulatory inputs to them and then remove homework assignment and everything and then let them kind of equilibriate to their homeostasis what are likely how many hours they're likely to sleep that turns out to be somewhere between eight and a half to nine and a half hours which also means that going back to sleep nearly 90 percent of high school students in this country are chronically sleep deprived because most high school students don't get nine hours of sleep on a regular basis maybe in the weekend probably because of devices yeah on iPads and also as I said this new idea that midnight is your assignment submission time I'll come back to that again and again I'm hearing that again again so teachers take note it's an issue it's a very interesting idea as a way to kind of anchor Behavior earlier in the day yeah learning to in I mean Public Health uh is complicated because people are incentivized by fear but they you know you get more bees with honey as they say right you know there's uh incentivizing people to wake earlier not necessarily with the sunrise but wake earlier and go to sleep earlier and eat within an 8 to 12 hour window um 12 if it's yeah so that's my children yeah it sounds to me like you know all these health benefits are what I think are going to incentivize people more than for instance this idea that well if you don't do this you're going to get Dementia or something right but like every day people will feel more healthy and more productive and so that's why I said that even if children are supposed to sleep for nine hours of course they're not eating during those nine hours and we're not uh feeding children and putting them down to slay because you know their core body temperature will be high they cannot fall asleep so at least they should have their last meal one or two hours before going to bed because typically parents feed them and maybe give them a shower or a butt and then they read the bedtime story so it's one to two hours before bedtime they're finishing food similarly on the other end after they wake up it's not that we're waking them up and then feeding them so hopefully we're not doing that so that's at 12 hours seems to be Optimum and it's not only I'm saying that if we put all the health recommendations together from pediatrists and then it makes sense um fascinating I have a question about structuring meal intake or food intake um during the eating window um I have a good friend actually he's um he's the neurosurgeon at neurolink now but he came up through Stanford and um and he has a habit of eating of skipping one meal per day within a feeding window so it might be breakfast lunch skip dinner one day then it might be breakfast dinner the next day lunch and dinner the next one so it's not in keeping with the same start time always but the end time is either going to be earlier or there's a gate it's never later yeah it's never later um what do you think about that as a strategy um you know in many ways it feels like that fits with the way that a lot of people's lives run so sometimes for instance if I'm in a podcast I don't tend to eat much in the middle of the day because it makes me a little bit groggy the post perennial dip in energy so I'll do breakfast well but again at 11 and that's a first that's when I break my fast 11ish and then dinner maybe a snack in the middle of the day but other days it's three meals so does it matter um overall as long as um one isn't allowing the start time and the ending time to drift out is it okay if you go from 12 hours to ten to eight eight ten four twelve as long as you don't exceed that the the brackets are you okay uh so this is where the Circadian aspect come in because if you're going um if you're moving that breakfast time or dinner time three four hours essentially causing maybe a metabolic jet lag you know in short term in weeks months or maybe even few years you may not see any change um at the same time we don't know what is the long term consequences one thing is we always think I'll come back to this point again and again we think that a body weight is a marker of Health or body composition is a marker of Health it's not always true because as I said issue drift locks um filling um you know having some Pang of depression or anxiety or LDL like high LDL a lot of thin people have or low body fat people have very high LDL yeah so those are the things that um we don't connect with our habit and since security under them and meal timing meal structure now is a very new um field um I think good studies will come out only in a few years because right now people are just going back and retrospectively looking at some Diet record one day of diet record and trying to glean too much out of it but I think hopefully things will improve where people will become it will become standard to at least look for one week of diet record meal time and what they're eating all that stuff because uh are now Mouse studies also showing what a front loading carbohydrate or front loading fat or protein has benefit over so I think this studies are starting so I should not comment whether that's good or bad no I think it's great to hold off until then we have you back on to discuss um I have a question about um fasting on the longer term um and there it's a near Infinite Space we could explore of two days of fasting one day I know people that every once in a while they just decide I'm fasting they've either been eating too much at parties or they're not feeling well or whatever they just decide I'm fasting for 24 hours and um they'll still consume water and caffeine but they'll just fast is there any health benefit or detriment um you mentioned the circadian clock shifting effects but if somebody wakes up on Sunday and they you know they ate too much or they feel they ate too much or they don't like the food they ate on Saturday they're not really feeling it and they're just going to fast into Monday is there any known benefit or um Health detriment to doing that kind of thing yeah there's a actually a rich literature on this complete fast um an impact in many religions people practiced complete fast as you were to cleanse their body and people have seen that there are benefits to that so in fact the every other day eating in Mouse model or even in humans are also initially some studies were done there are many health benefits and right now there are even fasting clinics in Germany where people check in and they're under strict supervision and then they do complete fast or maybe a small bowl of soup which has 100 200 kilocal and that's all they get to eat sometimes two three days four days five days even they have gone up to three or four weeks for sake of weight loss is that why from many different things and um they come out pretty well healthy of course they're under supervision make sure that they're getting macro micronutrients sorry the micronutrients vitamins and electrolytes so those studies are pretty solid people have observed that and then in fact there are even idea that fasting this kind of fasting can have huge impact on brain and people may come out of treatment resistant depression or something but you know so those studies are very difficult to do they're only case of one here and there that we hear once in a while but hopefully in future we'll see um whether the depression anxiety the mental health aspect will benefit from fasting because now as there is more and more evidence that there's this gut brain axis and whether the presence of food or the microbiome changes in the gut if they can affect brain then maybe long-term fasting periodic fasting a few days of low calorie diet back to back will be interesting to see how it impacts brain health very interesting what are your thoughts on fat fasting where people try and limit their blood glucose by only eating mainly fats mainly healthy typically they'll eat healthier Fatso of avocados olive oils and nuts you know and some animal fats perhaps but um as a way to keep blood glucose low and also time restrict this goes back to the kind of low carbohydrate um thing what are your thoughts on that as as a general strategy for health I mean it combines sort of two general themes that are out there I think both of which are you know data are still incoming that restricting the feeding times it can be beneficial as well as keeping overall blood glucose lower can be beneficial yeah I think there is too much uh emphasis now on blood sugar spiking or um we don't know um this kind of eating pattern for example means we are essentially telling pancreas that okay it's or the eyelid cells that produce uh insulin and it's okay you can take um take a break go on vacation for you for a month or two or three months um my question is it will be interesting to see what happens to those eyelets because for example we know that if we this user unused our muscles that is muscle atrophy muscles will become weaker we don't know whether long-term consequences of this very low carbohydrate diet where you are not essentially engaging the eyelid cells periodically what is its impact so if there is no impact maybe it's okay maybe because as you know many people who actually work on ketogenic diet the researchers themselves they find it very difficult to stay in true ketogenic diet because the true ketogenic diet is consuming less than 10 percent of calories from carbohydrate and not very many from protein a lot of people think ketogenic diet allows them to eat massive amounts of meat and that's not necessarily the case just one clarification for people um uh Sachin was referring to islet cells of the pancreas which are the ones that manufacture insulin so the question is whether or not taking in low levels of blood glucose by way of a low carbohydrate diet those islet cells are going to shut off their production very interesting I mean the liver is a very plastic tissue I mean it tends to um react very dramatically to to Lifestyle Changes yeah so that's why it was interesting to see what happens means we know that even muscle issues for example people who become bedridden the loss of muscle mass but when they come back and exercise they gain it back so it'll be interesting to see what happens in these people who are going through long-term ketogenic diet and of course once in a while because of social pressure or something else if they don't have access to food or something happens they may consume some sugar some blood glucose will Spike but it's not that every spike is bad I mean the reason why we have insulin is for good reason to buffer that Spike to buffer that Spike and also you know people always say that well if you have insulin produced or insulin like growth factor those are really bad and it should avoid that and I think that's a little bit extreme and I mean that's the insulin growth factors involved in muscle protein synthesis tissue repair yeah maybe even cognition so yeah yeah and it also goes back to as a m tour activation and all that stuff people get really excited about how to reduce them to activation rapamycin and all that stuff so this is where um again from circadian point of view um I ask people to think okay so two very popular drug like molecules or drugs that people think will increase longevity or metformin which many people agree not all will come to a consensus that it activates MP kinase or the sensor and the cells that sense that your cells are fasting so metformin kind of activates it so that it kind of you can say although it may not be scientifically accurate uh the um you know fasting and appeal so it sort of mimics fasting yeah and the and the thing I'd lump in there with metformin is that berberine is kind of the Poor Man's metformin it's a tree bark extract that also dramatically lowers blood glucose yeah yeah and it mimics kind of that um fasting and then rapamycin um also kind of reduces Emptor activation and people have shown that rapamycin and Metformin can extend Mouse lifespan and in improve health okay so now let's go back to the calorie restriction study that I mentioned in calorie restriction people are giving food as a lump sum and they were essentially doing time restriction the mice were doing time restriction if we think about it during day time when experimenters are coming to the bivarium the mice should be sleeping and fasting and they should naturally have high level of MP kinase if they're truly fasting and they should also have low level of interactivity because M2 responds to insulin and that should go off at night so my suspicion is um in many of these experiments where the mice were allowed to eat at Louis Vuitton even normal standard Char now we are we know that as mice get older they actually consume little bit more food during day time which is the equivalent of human night humans nighttime it is like nighttime eating we know is an issue I didn't realize that was more of an issue as people age but yeah so we don't know but at least in mice because you know we can put demise in calorimetry look at every single by dieting how much they're eating so I guess it was natural to see that researchers found that there is some mtor activity during day time when the mice were not supposed to have M3 activity because they should be fasting and since they ate little bit they were snacking during day time amp kinase activity was not at its peak so giving metformin kind of mimic that fasting state and reducing M productivity by drug like rapamycin also kind of mimics some aspect of the fasting state so my suspicion is um since these studies were done always in mice who are supposed to be in the fasting State and both enter sorry rapamycin and mpkin is activated or metformin kind of are mimicking that fasting State that's why we have seen those benefits and it will be interesting to see if that experiment will be done in humans in the long term because many people are very excited about you know there is M total long-term metformin study and then a lot of people are actually consuming good amount of rapamycin off level they can get their own so that's my curiosity I'm not saying whether it's good or bad or whether there is science or not that's something that will be interesting to control for and see because recently I saw one of my again close friend and colleague at Scripps suited a very simple elegant study people should have done in metformin field so it took mice and then measured their blood glucose at different time of the day and in fact just like human blood Lookers our blood glucose fluctuates a little bit uh she saw that rhythm and then in every two hours or three hours um on different days of course so you have the same dose of Metformin to mice and what she found was a different time of the day metformin had very dramatic change in glucose reducing ability so which means that even if you take metformin and give a different time of the day for the mouse or even for humans in very long term of course in this mice this mice were not diabetic or anything they were healthy mice to begin with so in long term we might see um benefits that are very different so this brings to this idea that well maybe metformin say at the end of the day evening metformin May trigger that fasting State much earlier than end of digestion whereas metformin in the beginning of the day may not at least from longevity perspective I'm not talking about Diabetes Type 2 diabetes here so the same thing with Emptor um is mtor going to have much better impact if taken during evening morning before meal so um these are my thoughts that go along with all this fat um story that we talked about do you take Metformin or Burberry I know I haven't taken although you know um I have close uh friend and colleague um Ruben Shaw who is now the director of Cancer Center at salki extensively works on MP kinase and its mechanisms and um so it's always fun to talk to him he's a he's a fan yeah I've taken berberine before and I've had two different very distinct experiences with them first of all um berberine when ingested with carbohydrates in particular carbohydrates to have a lot of simple sugars definitely I know this because I measured my blood glucose I did the experiment allows you to flatten out your blood glucose response so you know in some sense if you're you know there is this idea if you're going to eat a particularly big meal or sugary meal and you don't want to get a massive blood glucose rise you take berberine or metformin metformin is yeah prescription that's I went with berberine because it's as far as I know it works as well yeah um at least for healthy people yeah for healthy people that's right um when I took berberine and did not ingest large amounts of simple sugars or carbohydrates along with it I experienced profound hypoglycemia I felt like complete garbage for about eight hours and I had one of the worst headaches of my life because which makes sense you just got a blood sugar crash so if you lower blood your blood sugar when you already have fairly low blood sugar and you're not ingesting carbohydrates you can really bottom out your your blood glucose so just say it's I say that as a for two reasons one is kind of a cautionary note and the other one that um when you think about the biology of these compounds it makes perfect sense and I think that um and I did not pay attention to circadian effects yeah yeah I mean you know when I joined Salk um is the kind of the um big liver and sick in metabolism and he works on nuclear hormone receptors um these are the master regulator of metabolism and normal cells cancer cells and many other and what was interesting was in the first few years Ron did a very simple experiment he just looked at what time of the day this nuclear hormone receptors are turned on at gene expression level and some are protein level and he found that almost all of them have a circadian pattern at least in some tissue so he went to that length to say even that circadian is metabolism and metabolism is circadian the reason why we have a circadian rhythm is to have a daily rhythms in food seeking behavior and eating and also go through a period of time when we should be fasting and then on the other hand all the metabolic Regulators also have to follow that rule and almost all metabolic Regulators everything that we can think of connected to metabolizing macronutrient protein carb and fat they should also have a circadian rhythm or diurnal cycle to align or misalign so for example fat oxidation should be in opposite phase with feeding and um you know in retrospect at that time it was kind of amazing to see Ron could foresee of course he's smart enough to foresee and predict that this is going to happen to circadian field because at that time we're thinking about the suprachiasmatic nucleus sleep quick cycle and we are not thinking too much about metabolism so that's the awesome thing about song being at Salt because we have 50 pis really crammed into two awesome buildings and with Open Lab structure so you bump onto each other and talk to you so and with an ocean view oh it's awesome view yes it's an amazing place I was lucky enough to have an adjunct position there when I when my lab was at UCSD and uh it is an amazing Place doing incredible groundbreaking work which of course includes yours listen uh Sachin I I'm clear now that um we have to have you back on for another uh series of discussions seriously speaking if if you'd be so so uh kind and willing to do that I want to thank you for several things first of all for your taking the time today to sit down and discuss these um incredibly interesting ideas in detail you know much of what we talk about on the podcast is uh obviously grounded in science and and often but not always as actionable and so much of what we talked about today is actionable in the sense that many people are already doing certain dimensions of these things some are not some are hearing about it and considering it you've given us dozens I've listed some out dozens of tools and considerations based on whether or not people are engaging in shift work or not I think a lot of people are going to realize that they are shift workers yeah even though they didn't think they were um because of the nature of their habits now to light and activity and so forth um I absolutely love the firefighter study because of its relevance to the general population also not another nod to fighter fighters and shift workers everywhere thank you and you know I think among the colleagues I've known for several decades now you really are one of a very small few who've managed to do both animal studies and human studies but also animal studies with a very clear eye and a pointer toward human health and um that's such a vital and rare thing especially in this day of um extremely competitive funding so I want to thank you for your time today for the knowledge you share the actionable aspects of that knowledge the science that you're doing in your laboratory we will provide links for people to learn more about you and of course to go to the app yeah um so people can um engage in some of the science directly and of course you have several wonderful books now that we will also link to both of which I've read and are wonderful in particular the book um the first book but also a book related to diabetes and um so for diabetics and people interested in metabolic and blood sugar regulation um there so yeah on behalf of myself and my team here at The huberman Lab podcast and all the listeners I just want to say thank you so much your time is valuable and the fact that you'd share it with us and educate so many people is really a gift yeah thank you and actually likewise there are very few scientists who have taken this leadership role that you have taken to uh come and communicate science to the public it's not easy because sometimes you have to distill it down to a simple sound bite to the point where the scientist and they'll say oh that may not be right but we always have to keep in mind that we are always living in the dark is of science because the reason why I say that this is not my quote actually this is from one of my scientific hero Paul simel from Scripps Yola says think about it 10 years ago what do you what you thought was right and the best has already changed but one thing is the Circadian rhythm and aligning it to our internal clock to our habit is very important and as you mentioned uh we have our my security and clock app which is research facing but we have also distilled all of this down to five or six timing component and we have a new app called on time health or get on time Health to people access that through the standard app stores yeah so now it's available in in app store uh sorry uh Apple App Store and we want to see uh how because people always think about fasting but as we discussed today feeding fasting or eating fasting and activity and sleep a kind of interlinked and we have to kind of balance both of these so that's that was the idea behind this on time health program and um thank you Andy because what you're doing is immensely necessary particularly these days when science is moving at a very past phase there are a lot of results coming out sometimes something can be very confusing and you spending your time to communicate science is exceptional so thank you well you're most welcome it's um days like today where I get to sit down and and talk to brilliant colleagues like you who are doing the important work that that really matters so much and so as you um mentioned a moment ago that there's uh a lot of darkness and confusion out there but uh thank you for being uh one of those whose Shining Light thank you thank you for joining me for today's discussion with Dr Sachin Panda all about circadian biology and time restricted feeding if you're learning from and are enjoying this podcast please subscribe to our YouTube channel that's a terrific zero cost way to support us in addition please subscribe to the podcast on both apple and Spotify and on both apple and Spotify you can also leave us up to a five-star review if you have questions for us or comments about the podcast or topics you'd like me to cover or guests that you'd like me to include on the huberman Lab podcast please put those in the comment section on YouTube I do read all the comments in addition please check out the sponsors mentioned at the beginning and throughout today's episode that's the best way to support this podcast on various episodes of The huberman Lab podcast we discuss supplements while supplements aren't necessary for everybody many people derive tremendous benefit from them for things like improving sleep supporting hormones improving focus and so on the huberman Lab podcast is proud to have partnered with momentous supplements we've done that for several reasons first of all momentous supplements are of the very highest quality and are used with various sports teams and various studies through the Department of Defense and so on and momentous supplements tend to be in single ingredient formulations single ingredient formulations are absolutely essential if you are going to develop the most cost effective and biologically effective supplement regimen for you because simply put they allow you to adjust the dosage of individual ingredients to alternate days that you take different ingredients to cycle them and so forth in addition momentous supplements are available internationally which many other supplements are not if you'd like to see the supplements discussed on the huberman Lab podcast you can go to live momentous spelled ous live momentous.com huberman if you're not already following me on social media it's huberman lab on Instagram Twitter Facebook and Linkedin and at all of those places I cover science and science-based tools some of which overlap with the contents of the huberman Lab podcast but much of which is distinct from the content covered on the huberman Lab podcast again it's hubervin lab on all social media platforms if you haven't already subscribed to the huberman Lab podcast neural network newsletter it's a monthly newsletter that includes free tool kits for things like toolkit for sleep how to enhance the quality and duration of your sleep toolkit for Focus toolkit for neuroplasticity toolkit for deliberate cold exposure heat exposure and summaries of podcast episodes all of those toolkits can be found by going to hubermanlab.com go to the menu scroll down to newsletter and simply give us your email we do not share your email with anybody and again the newsletters and toolkits are completely zero must end you will also find some PDF examples of previous toolkits again that's hubermanlab.com thank you once again for joining me for today's discussion with Dr Sachin Panda I hope you found the conversation to be as informative and actionable as I did and last but certainly not least thank you for your interest in science [Music]

Channel: Andrew Huberman

Views: 775,374

Keywords: andrew huberman, huberman lab podcast, huberman podcast, dr. andrew huberman, neuroscience, huberman lab, andrew huberman podcast, the huberman lab podcast, science podcast, circadian rhythm, circadian clock, Satchin Panda, Salk Institute, fasting, intermittent fasting, time restricted eating

Id: 7R3-3HR6-u4

Length: 169min 6sec (10146 seconds)

Published: Mon Mar 13 2023