Stanford nutrition professor: What to eat for your health - according to science

if you wanted to change cholesterol blood glucose inflammatory markers a lot of things like that can change in just weeks even when people went onto a longevity diet at the age of 60 they still gained many extra healthy years so we covered a host of popular diets are some popular diets harmful to your health those don't seem to work I actually want to go right back to the start what's the biggest myth is that there is one diet for everyone for many years American nutrition was a about penalizing don't eat added sugar don't eat saturated fat don't eat salt but they didn't tell them what to eat so could you start to unpack that what is a good way to eat in 2024 my first answer is I've been working with chefs a lot lately and he introduced a term to me actually I think this is an maybe an odd twist and you wouldn't have seen this coming I think welcome to zoi science and nutrition where World leading scientists explain how their research can improve your health I'm your host Jonathan wolf co-founder and CEO of Zoe each day this week we've examined the science behind the world's most popular diets and today we conclude our series and ask the key question what's the healthiest way to eat Professor Christopher Gardner has been my guest throughout this series and today we're also joined by Dr Sarah Barry and they'll reveal the answer on this show Christopher is a professor of medicine at Stanford University and the director of nutrition studies at the prestigious Stanford prevention Research Center Sarah is associate professor in nutrition at Kings College London and the chief scientist at Zoe ready for the Ultimate Nutrition takeaway let's dive [Music] in Christopher thank you for joining me and Sarah today this should be fun I'm very excited why don't we start with a quick fire round of questions and uh I think you remember the drill this is yes and no but for one question I get maybe a little bit of an opportunity to expand if you're very good we know we like it's like the prize for professors for managing to keep the rules at the beginning is then they get a whole sentence at the end he doesn't let me have a whole sentence you're very lucky Christopher so can I improve my health if I change what I eat yes are some popular diets harmful to your health yes is there one diet that works for everyone no should men and women eat the same diet yes is there one food that can drastically improve my health no see that was easy right oh yeah okay that was very easy so now you get a whole sentence what's the biggest myth about healthy eating that you often hear the biggest myth is that there is one diet for everyone if we just could find it if those scientists would just finish their studies they'd tell us the one diet we all need well that's almost sounds like an ad phor I love that Christopher so look throughout the last week we've been discussing popular diets in this series of sort of short daily episodes but before we draw sort of our conclusions from this and hopefully help everybody understand like how they can improve the way they eat to improve their health in 2024 I actually want to go right back to the start and ask you this why do people go on diets oh great question they they intuitively know that what they're eating has an impact on their health and they're not happy with their health there's so many people who have health conditions don't want to be on medications want to lose some weight it's pretty obvious for most of them that it's related or could be related to their diet and so what are the biggest sort of myths or misunderstandings that people are then suffering from when they decide hey I'm going to go onto a diet now to fix my health so for me the simplest answer would be uh there is a diet that I can do short term that I will eventually get to go off of and I'll be all set once I master that for now but then I'll quit and why is that a myth Christopher well because for anything to work it only works as long as you're doing it so once you go off the weight comes back on the cholesterol goes back up the glucose goes back up in the blood so it it only works as long as you're doing it so you have to do it forever if you want it to work for your life which is quite a challenging idea isn't it it's sort of saying hey you got to make a lifelong change to the way you're eating and when you think about it like that it also sounds really scary there'll be probably people listening to saying well you know I can't do that so therefore I should just give up um is it as is it as bad as that oh it's not as bad as that at all I have a PhD in nutrition science I'm still changing my diet to this day as I do more studies or learn of a different cultural food attribute that I like um yeah there there's you should be kind to yourself you should let yourself experiment I mean the beauty of food is let's and let's make it either eating or cooking let say you burned this recipe oh you're screwed you'll never make that recipe again it burned no you burned it turn the heat down next time or add a different ingredient or go slower so the beauty of food is you get a doover every day you want I love that and so I think one of the things that we hear often from people is a concern that it's too late they've been eating in a particular way for too long and so they are 40 50 60 70 80 and therefore it doesn't matter anymore my I think about my parents actually as I think about this doesn't matter anymore because it's all done and so it doesn't make any sense to change what they eat is are they right no for all these things that are risk factors that clinicians measure again this is blood cholesterol or blood glucose or weight what whatever it is yeah you can always enhance your physical abilities and your long-term health no no matter what age you approach this yeah and there's some really interesting research Christopher that came out a couple of weeks ago you might be aware of where they looked at how many extra healthy years people had that went from a very typical UK US diet to the recommended diet and what they called a longevity diet which is basically combining all of what's up here in your head and applying it and uh to people's diet and they found even when people went on to a longevity diet at the age of 60 they still gained many extra healthy years and you know I think that's really encouraging that people should really focus on actually at any time I can still make a huge difference yeah very encouraging it's amazing and Incredibly positive I think and so you were talking about this idea that people need to sustain this life um this lifestyle sort of permanently and so I guess that has implications for the sort of of diet that people you know can you know should be adopting as we're we're discussing this today yeah you have to like it you have to enjoy it so I feel like which sounds a bit radical actually I'm laughing but that's because I feel yeah like I grew up with diet culture and I think many people listening to this did and the whole idea of diet culture is quite linked to the idea of calorie counting which we we touched on is like you're supposed to suffer in order to try and and improve your health which is also why you can't probably do it forever but I I'm sort of laughing because this idea that you might enjoy your diet feels like the opposite of what I was taught yeah so let me give you one of my favorite new phrases so after doing many studies uh and I'm just going to mock myself here and I'm sure Sarah could agree if we're trying to get an answerable question we'll focus on this one thing and uh okay so isolationist reductionist this fiber Works what's the best source of fiber cardboard we've given you cardboard it has lowered your cholesterol go forth and eat cardboard I don't want to eat cardboard but I showed you it lowered your LDL cholesterol so I've been working with chefs a lot lately and I've been working with a lot of chefs that are interested in plant-based diets and Greg drer is one of the leaders of The Culinary Institute of America in the US one of the largest cooking schools in the US and he introduced a term to me years ago about Unapologetic deliciousness first it was craveability which I really liked I thought people are going to like that but when he said Unapologetic deliciousness I I think a lot of people would like to eat that way but it struck me in a particularly strong way because I remember myself for years apologizing like I found the cardboard will help your LDL I'm scrunching up my face because I'm sorry that I'm asking you to eat cardboard but works I proved it in an NIH funded study in a randomized control trial and I'm I'm sorry it's so painful and restrictive but it's the truth and Greg sh Greg rusher said you know we can make anything taste good we'll make this Mediterranean Middle Eastern Latin American African dish tastes great it'll be plant-based it might have some animal Source food but a lot less than you eat in the US but it'll be amazing I thought ah I want to stop apologizing I want to say this is unapologetically delicious because in terms of maintaining something longterm that's what you want you don't want to be punished and penalized your whole life yeah I'm a great believer in if a food's too healthy to be enjoyed it's just not healthy at all and you know big problem we have isn't just that we're eating the wrong kind of food it's that we are not adhering to any of the kind of recommendations because like you said that lots of these foods are you know they don't taste great they're very restrictive these kind of diets as well and in the UK less than 1% of people actually follow any kind of healthy eating guidelines it's the same in the US and so there's no point telling people to go on this kind of diet to eat these kind of foods if they taste rubbish because you won't adhere to it long term and that's why all of these or many of these diets fail Sarah I love that and I would like to pull you in as a fellow geek here um we run studies we randomly assign people and I think a huge problem that people have and their frustration with nutrition is what looks like misinformation in the scientific literature and the media that covers it one day this one works and the next day it doesn't and the word that really struck me that you just mentioned is adherence and we both go to Great pains to have them self-report what they're eating and that that's better than not self-reporting but at some level I'm sure some of them feel like I they told me to eat this and I better tell them that I did because I'm in a study and they didn't really eat it and what really are what we're really missing is the Nuance of individual variability and how each person in that study followed it a little differently and as frustrating as that is it's kind of fascinating to think of the personalization opportunities there that are always always coming up hi I hope you're enjoying my conversation with Christopher and Sarah as much as I am and in a minute you'll find out what their top tips are if you want to change your diet but first I have a favor to ask 63% of people who watch this podcast haven't hit the Subscribe button and 11% haven't yet hit the Bell to turn notifications on we want this podcast to reach as many people as possible as we continue our mission to improve the health of millions so if you've ever enjoyed this podcast please hit the Subscribe button and turn notifications on doing us a small favor will really help thank you and back to the show so we covered a host of popular diets throughout the last six days and some of them were really extreme and restrictive which I think is interesting given this discussion we're having about the challenge of Something's restrictive so like the carnivore diet or the keto diet or indeed I think you were talking about this very lowfat vegan diet as well and then there is calorie counting which basically says you've got to restrict yourself the heart of what you're doing is um restriction uh and then there was the Mediterranean diet which only the way that you were selling it to me Christopher tasted you know I could taste it even as you were talking about it and felt a lot less restrictive so I'd love to draw some conclusions about these diets before we then talk about okay what what do you think is best so maybe start with what are the worst diets for our health uh the worst ones are the ones that are most restrictive and most animal-based which is uh the highest sources of saturated fat and the lowest sources of fiber and so and why is that why they why do you feel like that's what makes them worse the restriction and the animal fats so the Restriction that part is it's hard to maintain any restrictive diet is hard to maintain but of all the things that we can come up with in nutrition where you can actually trace it back to a nutrient the two the three easiest on so actually let me bring up a third would be saturated fat for your LDL cholesterol bad fiber for your microbiome good and added sugar and refined grain for excess calories and a poor Metabolic Effect so uh I will say that pretty much all the diets that are out there and we've just published an American Heart Association overview of popular diets all of them even our favorites and our least favorites said less added sugar and less refined grain let's have a Kumbaya moment can we just have a big hug and pat on the back we have consensus on that point and in this paper that we just wrote We tiered the diets in four tiers and the lowest tier just in terms of matching up with American Heart guidelines for being a heart healthy diet keto paleo and Atkins were all in the lowest tier published paper I I think another thing that a lot of people feel is you know particularly at this time of year they feel you know what I think I sort of overindulged in you know November and December and I'm waking up in January and I know that that has impacting how I'm feeling so I know that what I'm eating along with probably other aspects of my lifestyle to do with how much exercise is really affecting my health and I and I want to feel better now like I really want to feel much better um I want to many more healthy years in the future I for many people will say I'd really like to lose some weight because I feel like I can see that this has been sort of you know slowly going up and so they would like to be able to do something which is going to give them you know a fast um effect on that so I think to me you know not being a nutritional scientist there's a lot of logic for that and so I guess what would you say to people therefore as they're thinking about how to change what they eat given you know that's what they want and they don't only to be told well you can wait 10 years before anything happens yeah well a lot of the things that we do in diet work in four to eight weeks MH if you wanted to change cholesterol blood glucose inflammatory markers microbiome a lot of things like that can change in just weeks we've just published an 8we study assigning identical twins to vegan or omnivore and the studies were there at 4 weeks and so a lot of the participants looked at that and said wow this is amazing I didn't really appreciate that could happen so quickly and so you're saying you know people listening to this you can really change how you feel and like even markers of your health you know things you the the doctor could measure in your blood you know in just a a few months without having to go for like you know these sort of extreme ketogenic diets or or or something like like that so and I'll get Sarah to chime in here so you you do get bigger effects the bigger the change that you make but My worry is the bigger the change that you make it might be the least likely that you will continue that change so my personal approach for most people say think of the worst couple things that you do and just get rid of those and find something to replace them or find something that you already do that your nutrition consultant likes and do more of that take something more reasonable but if you really wanted something quick you you could see it if you made a big change but if you want it to last it should probably be slower just like weight loss issues if you see anybody losing weight very rapidly they're very likely to gain it back a more healthy thing is a pound a week over a long time will last longer and I think to focus on one change that is going to have that bigger size impact is really important and we see in our studies for example cholesterol can change in 10 days after two weeks you see quite a big difference after four weeks at plateaus yes and so any dietary change if you were to go to the doctors and have measures done you do see that change what we don't see is obviously externally the change and that's the problem so people maybe not realizing wow you know making these changes have really had a big impact internally on my health yep so before talking about what people should eat which is obviously what they're really interested here I did want to ask about why there's such a big gap between the scientific evidence that um you know both of you talking about right now on topics like calorie counting and sort of lowfat food and then what we see on you know the food labels when we go to the grocery store or Official Guidelines where basically you know I looked again this week you know you you walk in there and like everything still says low fat on it unless it says high protein um and there are calorie labels everywhere and yet you sort of De demolish both these approaches to thinking about how we should eat yeah the the communication part is the hardest so the studies that we do are complicated they don't really have one simple interpretation uh and part of the reason for the labels is the food industry recognizing that they want a little bigger share of the Market's stomach just a piece I can answer my shareholders if I get that what's the current thing they just said oh they said that okay I'm going to add it to the label and Shoppers want something convenient like oh food is confusing I'd really love to go into the store and have a simple thing that will help me with my choices and sadly it isn't simple I know they want that help I know they want to be straightforward and I know the food industry wants to make more money and it works some of that advertising works and we're just caught in a bind trying to communicate what we find in our studies and make it simple for everyone when it's almost never that simple sorry listeners yeah I think this is the real challenge I find that we know that foods have thousands of chemicals we know that these chemicals are packaged in you know the structure of the food you know I'm particularly interested in the food Matrix so how the structure of the food modulates the health effects of that food none of this can be captured on those food labels but we as nutrition scien need to make sure that our message is very simple to people but because of this complexity of food but also the complexity of how we as individuals process the food it's just to Nuance to communicate in a food label and so it's a real challenge that we have and I don't know how we can tackle this the answer is just to get people to think more critically I mean to to actually I think this is an maybe an odd twist and you wouldn't have seen this coming I think think food is an opportunity for people to think more effectively critically in ways that will help them in the rest of their life I don't understand politics I don't understand War I don't understand this other thing you're not thinking critically there's more than one side to this argument so think through this logically recognize the limitations recognize the strength and make the best choice you can today can actually be very empowering in the long run but you do have to engage so I'd love to start to talk about what people should do so we've sort of said hey there's a whole bunch of diets that don't make sense and in fact the whole idea of a diet something you do for a period of time doesn't make sense you've got to shift to thinking about like how am I going to eat for the rest of of my life I'd love to talk some more about therefore what we should eat and Christopher you said to me you know before this recording like the number one thing people say to you is Doc what should I eat so let's you know maybe sort of make that step um you know what's the starting point for answering that question okay and I think Sarah's going to be with me on this one my first answer is it depends absolutely my next two follow-ups are please tell me with what and instead of what and where yeah where are you now so you know if somebody says uh I'm really thinking whether I should eat eggs or not and I said well what were you gonna have otherwise and they said well I was going to have steel cut oats or eggs I said well I don't know what were you going to have the eggs with I said well I was going to have sausage and bacon said ah okay so I really think you ought to have the steel cut oats instead of that oh I didn't mean that I meant a veggie omelette I said oh veggie omelette steel cut oats yeah not too bad pretty equal I'm fine with that or they said I was going to have a Pop-Tart said oh my God have the eggs God forbid you eat that Pop-Tart right and so if you put it in the context of with what and instead of what they could often answer their own question for you knowing that part yeah and at Zoe we often talk about swaps so it's a simple way of really explaining what you've just or putting into practice what you've just explained so we say okay this is what you're currently eating that isn't so healthy this is a healthier swap so it can be used in the same way because we have to be practical there's no point recommend either food that people don't like like we've already said but also that isn't used in that kind of traditional breakfast setting or snack setting this really ties into there's been a a shift in American dietary guidelines so every five years they update the dietary guidelines for Americans and two or three Cycles ago they made sure to talk about shifts so for many years uh American nutrition was about penalizing don't eat added sugar don't eat saturated fat don't eat salt but they didn't tell them what to to eat and a colleague of mine David Katz loves to phrase this as Americans are incredibly clever you know they will find an unmeasurable number of alternative ways to eat poorly once you ask them to avoid this oh I found another way that's poor to I found another way well that's poor two because we didn't tell them what to eat it was easier tell them to tell them to avoid that hi I want to take a quick break here and tell you about something new and very exciting we've created a free guide that can Kickstart your journey to better gut health now if you're a regular listener of this podcast you're no doubt already aware of how important the gut microbiome is it's responsible for so much from digestion to immune support even our mental well-being and as we've heard many times on this show and as our members know through using Zoe we feed our gut microbiome through the variety of foods we eat and in return our microbes give us this wealth ofal health benefits so how can you nurture your gut in the best way which food swaps can you try to nourish those good bacteria what does a high fiber shopping list really look like our free gut health guide shares it all emails and actionable tips that are designed to put you in control of your gut health and to get yours for free simply go to zoe.com gut guide and you'll also find the link in the show notes and I think you touched on the it when you were saying that the Mediterranean diet was the one that you were um most positive about in terms of the the um the different diets that we've unpacked over the last six days what what is a good way to eat in 2024 yeah and it you know there's different names and different approaches if I had to ask you know in the three seconds I would say Whole Food plant-based and whole food means just not the processed and refined things so you take the the wheat berry and you've turned it into flour for bread no eat the wheat berry you've taken the brown rice and turned it into white rice you've taken the soybean and turned it into soy protein icelet and added it to a protein bar no no you should eat the whole soybean so that's what I mean by whole food and plant-based means you don't have to be vegan or vegetarian here but boy people are eating a lot in the US in particular we eat more meat than any other country in the world so you don't have to give up all of that but give up a lot of it and have a plant-based meal this is where the mediterranian sort of uh grain and bean based dish which globally has have been Staples for many many years in many cultures partly because they're uh they store easily and they're economically feasible grains and beans are pretty simple food bases to start with and that's why spices are so important so get you know Moroccan spices Mediterranean Latin American Middle Eastern Asian Spice them up and then you can add smaller amounts of fish or poultry uh or pork something in smaller amounts of wheat so the chefs that I work with for this Unapologetic deliciousness do something called the protein flip where the base of the meal is grains and beans and veggies and then meat becomes a condiment or a side dish or just a small portion on top of that so to me that's very Mediterranean and uh has lots of flexibility for enjoying what you're eating and in a way that sounds very simple but I think for a lot of people listening to this also quite unclear in comparison to diets where based on this idea you have to remove this thing because it's sort of killing you or causing problems or basically everything is about calories you know you're measuring your calories so obviously you're not going to get better unless you reduce your calories because that's what is about so maybe we could take those two parts one after the other like why is Whole Food better than processed food after all I chew it all up and it goes in my stomach I always I remember discussing this with my children at various points you know when it's all messed up they're like oh it's okay it's going to be messed up in your stomach anyway so you might as well eat it that way so why is it that um we can't have it all nicely sort of processed and prepared by the food manufacturers we're busy people and we have to have this sort of whole food thing that you just mentioned okay so I'm going to ask Sarah to help me fill in on this because satiety and satiation are huge factors in all this that are harder to study than we think yeah and Christoper means how full you feel because I know you would want us to give a simple term for that and so this comes up for me all the time thinking so one of my favorite authors is Barbara rules who wrote a book called volumetrics years ago and it was the volume of the food that was filling people up and the volume tends to be much higher if it's veggies and beans and grains than if it is cheese or meat or dairy and so eating this very satiating meal so that you get full quicker and stop eating and that it's longer till your next meal really helps here as scientists this is very hard to study so I've done a number of studies where I've got diet a and diet B and what I'd really like to know is after three months in the study how hungry were you in March how hungry were you in April we don't have any metrics like that all the metrics for this concept of satiety are I gave you a standardized breakfast at 8:00 a.m. it had 600 calories and two hours later I had a line from starving to very full and I marked on the line where I was in between okay how does that work for April why I can't tell you for April I can only tell you 2 hours after the standard 600 calorie breakfast and so it's a it's actually a harder concept to measure than you would think I mean you can just qualitatively say so how hungry were you and people give quite a varied response well I have some good news for you in our Zoe app every week we ask people weekly not just after each meal how hungry have you felt this week so we will be able to look at people's diets and tell and answer that but we have also collected data in that oldfashioned way but um where they do on a scale say after meal how hungry they feel um I often think about the health effects of processing also around the the idea that you've talked about like the instead of what so what's happening is is we're removing some of these great nutrients you know the fiber um some of these bioactives that we often talk about as nutritionist so uh polyphenols we're adding in the bad nutrients the salt the sugar you know the refined carbohydrates the saturated fat we're eating these Foods more quickly so not only are they more energy dense like you say filling up our tummy but we're eating them so quickly that that's another reason our fullness signals aren't getting to our brain in time to say whoa Christopher you've eaten enough slow down and you know all of this means that we're overc consuming the wrong nutrients dare I use the term nutrients because I know you like me are very food based rather nutrient-based um eating less of the good nutrients and eating in the wrong way as well yep and Kevin Hall's done a nice study like that again they were people who were confined and a lot of control was over this but had an ultra processed versus a minimally processed and timed how fast they were getting the calories and much to your point when they're eating the more heavily processed food they're eating more calories faster 50% difference in the rate at which they ate those calories between the ultra processed and the unprocessed foods which led to about 200 calorie difference I think over the day and it was hard for that message to get to the brain Y in time to stop you so I think you're saying there's like two effects here one is that the more processed food I'm just basically going to eat it faster it may even be designed so that I you know don't want to stop eating it so I'm just going to end up consuming more calories but there's a the second part which is you're saying the food is just worse for me when it's been really processed that you're losing a lot of things that now scientists understand are really important to us and I think Sarah you mentioned you know like the thousands of chemicals in our food right because most people listening to this are like aren't there like seven vitamins isn't that basically what there is in food because you see them you know on the great big labels on breakfast cereal like hey this vitamin and this other one has been added I've got a colleague named Michaela Kieran who approached this in a wonderful way said okay you know pick this thing that you think is not so good in your diet that you'd like to replace place and try at least five things to replace it and if you're going to replace it replace it with something that is as good or better as opposed to there's a thing I want to get rid of I tried an alternative and it wasn't as good so I didn't do it and I went back it takes some time but once you've put in that time and you've replaced that thing with something as good or better you have a changed for the rest of your life that you made and that's again now it's part of your lifestyle you know where to shop for it you know how long it takes to make make it you know what you need ahead of time and for me that's why it's important that this is a journey and not an overnight thing I tried five things it took me weeks to look for other options but now that I've got it I mean think of everyone who regardless of what their diet is if they were pushed there's three or four things that they know they like that they could get quickly and so to tell them don't do that anymore have this other thing oh the other thing isn't going to be nearly as quick as a convenience of course not not until you get accustomed to it and then it will replace that and it'll work just as well now you touched on sort of I think the first part there for what you describe sort of Whole Food not processed and how you know if this food ends up being really processed like one we just digest it really fast and you get these great big blood sugar spikes and we've talked about some of the negatives on that I think over the last um few days and then I think Sarah you're also talking about how you lose a lot of things that are stripped out can we talk a bit about the other parts so plantbased um which I think you know for some people listening is like what does that mean like plants or things in the garden and why is that a good thing and how does that tie in with the Mediterranean diet you talked about before sure CU that I mean that some of the key things that we came up with from the reductionist days was highs saturated fat and uh versus low saturated fat or Fiber being good for you so plants have fiber and animal Foods don't have fiber very few plant foods have saturated fat all the animal foods have saturated fat so if you just wanted to start overly simplistically that's a place to start to include more plants in your diet and why is the fiber good fiber is good for the microbiome it's the food Matrix it slows the digestion so that the carbohydrates that you are eating that are going to turn into blood glucose appear slowly over time say iting uh it'll help you feel full sooner it'll last with you longer um this is something we're really interested in as well because we know that fiber is like the party food for the microbiome as well and that's why we see the strongest signal so we see that the association between fiber and a healthy microbiome is incredibly strong we know that fiber is one of the single nutrients and I know again we hate to talk about nutrients that is associated with improved health and and I think that one of the strongest reasons is because of the impact it has on our microbiome as well as these other mechanisms you've done some research as well haven't you um looking at this I'd love to hear those results because I know it's quite a new study that's come out yeah so we've been messing with fiber and fermented food and the microbiome and trying to characterize this we're actually way behind you so we looked at some of your Publications to see what you're coming up with because we don't from my perspective our lab hasn't generated a list of the top microbes or a list of the different kinds of fibers so at the moment we're kind of stuck with well since we're not sure have a variety of fibers because the fibers that are present in wheat versus nuts versus beans are not the same and it again sorry but it's complicated so you can't just pick one fiber for one strain of bacteria that you're trying to look at uh the growth or the bloom of one of those bacterial strains has a an effect on the rest of the community but that's what I love about Zoe is how you're after that you're after the complexity because you can measure the fibers and you can measure the microbes and this is why we talk about diversity so much because we know that there's no point just focusing in on one fiber or or one aspect of of a food that we have to make sure we have a diversity of all the different bioactives and all the different kinds of fibers so Sarah someone thinking about right now for what that means for them to eat cuz it sounds cool right I want to support my healthy bacteria and get all those health benefits but what does that mean if I'm thinking about what I'm eating what what does that imply uh so when we talk about a diversity of food we tend to be wanting people to have a diversity of plant-based Foods so we talk about having eating the rainbow so eating the rainbow means that you're getting lots of different types of polyphenols polyphenols are these magical bioactives that are in food that give food their pigment so their their color so by getting a whole Rainbow Food you're getting different polyphenols but you're also going to get a variet I'm guessing my red poptart coming back to a previous comment that's probably not the polyphenols that are coloring it is am I right in guessing this no I'll use uh Christopher's terminology so Whole Food plant-based um are the ones that we we want to be encouraging and having a diversity of different plant-based Foods because exactly like Christopher said they have so many different types of fibers and because we know that different B bugs different bacteria feed on different fibers we want them all to have a party and we want them all to be growing um and all be producing the chemicals that we know have such a wide impact on our health and before we move Beyond this I'd love maybe to talk for a minute about the fat side of this because one of the things that um we know we touched on um during um the last six days is how many people still basically feel that they're really averse to adding fat into their diet because they were brought up when it was I think about my own family you know I was brought up there was super lowfat diet as I grew up because my father had high cholesterol and he was told by doctors you know even before I was born you need to eat low fat so I definitely grew up in that environment where I still find in a way the idea of like pouring oil over my food which I do a lot now but it's still like it still feels like a little naughty which maybe is one of the things that makes it I enjoy it and Sarah I know like this is one of your core areas of of study for um for the last 25 years you know if people were understanding um what healthy fats are and they were also looking to understand what they could add in what is the latest science saying yeah so and this is a nice way to tie back to fiber so plant Foods rarely have high saturated fat so if you're getting an avocado you're getting fiber if you're getting nuts you're getting fiber seeds you're getting fiber eating olives you're getting fiber so you could get the fiber and the mono and polyunsaturated fats those were all quite high fat foods that you're describing even though they weren't actually oils and they weren't maybe what people think of necessar Ling all foods plant-based foods that have a fair amount of fat in them nut Butters that you could spread on things I I'm certained that there's still this perception that you know low fat reduced fat no fat alternatives are healthier for you and I see these in the fridges of people that I know are on on weight loss diets and honestly I just it worries me that there's still this perception out there that if they have a lowfat food they're going to magically lose weight and also don't realize that by a food having low no or reduced something's come out of that food what's gone in to replace that yes because of this lowfat stigma um very focused on low fat yogurt which happens to be full in the US of sugar y like they'll have a fruited yogurt this is uh passion fruit or guava or Blackberry or passion fruit Blackberry guava yogurt and you look and it's full of sugar it's like a sugar delivery system it's like they took out the fat this is not healthy for you they took out the fat because people are afraid the fat is bad for them and they filled it with sugar which is probably worse than what they started with and I think this is a great example of how our knowledge of food and the health effects of food and nutrients is evolving uh so rapidly so there was evidence to show that dairy fat was bad for us that it's high and saturated fat that maybe a high total fat intake when it comes predominantly from saturated fat is bad for us we now know from randomized control trials and other evidence that fermented dairy fats so fat in full fat yogurt fat in in cheese isn't bad for us it doesn't raise our cholesterol and it's very difficult to keep up with how Sciences evolving and this again is the challenge and and so I think this is why there's these kind of products out there that's preying on people's ignorance unfortunately um but also Christopher going back to what I know we we've been talking about earlier fat makes food taste great yes it carries the flavor it has that creamy mouth feel as well and so listening to all of this you could start to say okay so there is one like one diet one way of eating which is the best for everybody like is that the you're really pushing on this one Jonathan so tell me about that and I know Sarah you were saying earlier we have to mention one of um Christopher's fantastic studies you know exactly around this yeah so so we did a large low carb versus low fat study and uh the approach we took I I think was fantastic I'm very proud of this we wanted to be a healthy low carb and a healthy low fat because when you just say low carb or low fat how low and which foods you I I can easily come up with a poorer and a better diet uh that both carry that name and are low in carb or fat when you put Good Foods um this is where the personalization thing comes in again after seeing many studies go back and forth on low fat and low carb we did a study that lasted a year a weight loss study and 600 people which is a pretty unusually high number of people and the weight loss difference was virtually identical in the two groups after year but the most stunning thing for me was how variable the responses were to the two diets so in both diet groups somebody lost 60 pounds in both diet groups somebody gained 20 pounds on a weight loss study oh my God they gained 20 pounds in a weight loss study so there were like some people who would put on low carb and put on weight and there were some people who put on low fat and put on weight and the reverse and the reverse and I was not calling out uh outliers so what's really fun is we grafted for every one of the 600 people 300 on each diet you know what was the result for each person it was absolute Continuum somebody lost 60 pounds oh should we do kilos here no let's we're let's talk pounds 60 pounds somebody lost 55 50 4540 all the way to the other end of gaining 20 why they got the same advice so how could it be these two diets which were quite different they were very statistically different in terms of carbon fat so what's the answer and the answer so the answer is we need to find more areas of personalization in fact our study was done to test two of those areas it was never done to test low fat versus low carb we thought there might be a predisposition that people who are genetically predisposed because of some genetic mutation one way or the group that was the most insulin resistant versus insulin sensitive would help explain some of this and the literature supported that that might be an explanation for the variability neither of them work so Sarah what's going on well I just want to say Christopher what I love about your study is that if you look at the average change in weight they're exactly the same between the two groups and I use this in a lot of my teaching to show that we need to move Beyond looking at the average looking at the mean of the population and this is what dietary guidelines are based on the average response to food and your study really clearly shows that that if you look at the average they're exactly the same but if you look at how each individual response it's hugely different and we see this with our Zer predict research that we see a 20-fold difference from one person to another in their blood sugar response to exactly the same meal yes so for example we fed people exactly the same breakfast we controlled as many of the other conditions that we know impact your blood sugar response so they had fasted overnight they' done no exercise um and we still found this 20-fold difference which is huge to giving them exactly the same breakfast and this is what we've been exploring as you know with all of our zo research what's causing this how can we disentangle this given that the food so complicated we're so complicated our biolog is complicated and how we live our life is so complicated yeah and it you won't know tomorrow right oh you're going to know the next day okay so you won't have all the answers soon in the meantime everybody if they chose a whole food plant-based diet some are likely to do better on higher fat and lower carb some just the opposite yeah that's not bizarre that's almost that should be expected so for now they shouldn't just throw up their hands and say ah there was no difference on average I'm going to go have a pint of ice cream because the nutrition scientists can't agree on anything no no no if you talk to us we actually agree on a lot of stuff it's it's just nuanced and we are waiting to do some better study so you should still eat well today and we have some basic guidelines but stay tuned because we have some exciting developments in work I'm struck Us by this conversation is sort of the logic behind why we do this podcast at all we we want to make the latest scientific information available for free to anyone who wants to listen and the reality is food is really complicated and understanding for yourself how to take the way that you eat now and how can you adjust it in a way that's healthy for you and navigate the complexity in the grocery store and how you cook it given all this complexity about like is that really a whole food is that really process not process is hard and I think this is one of the reasons that um you know we see the level of success that we do for people following um you know their Zoe program is this ability to get this like day byday guide and help you to understand exactly how these meals really score for you allows you to you know increase your chance of success because it really helps you navigate something that is complicated before we wrap up I feel like we focus a lot in a way on this past history of of diets which are about like the particular foods that you put in or not and I feel like a lot of the focus on the sort of ongoing nutritional science is more about sort of the ways in which we eat um and so I'd love you to maybe just pick out a couple of the things you know that that you're really excited about that I suspect we may be talking more about this this year so Jonathan's being very kind to me here Christopher because my my new passion is all around how we eat and I've been working very hard to convince him that this is something that we should focus on in zo and we are now focusing and it's now becoming part of our advice which I'm really proud of and so I'm a great believer in as well as what you eat as well as who you are how you eat is incredible ibly important and it's something I think we as nutritional scientists haven't thought enough about in the past and so we know from our own research how much sleep you've had impacts your blood glucose blood sugar response the next day we know that Tim restricted eating is a really simple way to be able to improve your health without changing necessarily what food you have and I don't mean time restricted eating having like a six-hour really restrictive window even having a 12-hour period that you don't eat overnight has incredible health benefits we know this from the big if study our big intermittent fasting study that that we did we know that how fast you eat food impacts your health and we've actually published some research about looking at how people on our our zoor predict study who ate fast versus those who ate slowly had different blood sugar responses different viseral fat different uh body mass index as well and we know the time of day is important so we know that for lots of people having carbohydrates earlier in the day is more healthy for you than than having carbohydrates later in the day again it's not the same for everyone but if we can combine all of this I think this is a really simple way that we can also again optimize People's Health but allowing people to make some small changes that fit within how they live their life without overw worrying about trying to get everything perfect so for example just not snacking after 8 at night trying to put your knife and fork down between each uh mouthful at the dinner table um and you know trying to be a bit careful having really refined carbohydrate later in the day and adding some of these in into the mix as well I think is really um magical way that we can easily improve our health as well I wonder what your thoughts are on this yeah and the key to that is having large bodies of data over time where you see people doing different things so I think you're doing some excellent work that's going to lead to some randomized control trials where you say ah we've got a signal from this data set that we have that this thing makes a big difference and it looks very compelling but we could do a new study to test that one thing but to get that that you have to have the ideas y so you're generating your own hypotheses for the future I agree this is a fascinating area and it it reminds me of of you know if you're talking time restricted or or those kinds of issues I often give a lecture where I'll say you know how many of you are useless unless you eat breakfast and a whole bunch of people raise their hand how many of you skip breakfast have absolutely no problem and you're fine and the other half raises their hand like what is this thing about breakfast is the most important meal of the day people are very different in when they start their breakfast what they have for breakfast wins their first eating episode so we know that's very personalized and so I would love it if you guys can use big data sets to pull together ah there's some hints at who those people are and you might want to test it on yourself and we'll do a study in the future but you're collecting a very powerfully rich database that will do that from all these citizen scientists that are joining Zoe and and providing these data it is obviously really exciting to be able to properly test these things and you know as as Sarah knows I was very nervous before we did the randomized control uh trial on like the Zoe membership because you basically there's nowhere to hide right does this really work if people you know do this product start doing the test get their results then follow all of this guidance using you know their app and then you know retest later does it genuinely improve their health um so I was very nervous and Sarah and Tim both said well we're not going to keep doing this unless we test this that's what you have to do as a scientist so it was very relieving to see that it um works and I think what is exciting is that you know we're continuing to use um you know all the new data to understand how to improve it and I do think that um you know it's really exciting exciting to see how much just in the data that we're collecting um how much it seems that some of these other factors like you know for some people the the time of day when they eat and time restricted eating you can really see these differences in Behavior so you know I think Sarah has convinced me this is this is pretty exciting yeah and it's just another tool in the tool box I think I would really emphasize people don't focus on a particular tool don't Focus just on time RCT to eating or eating rate or you know Focus like you said on a particular food we've got so many Tools in our tool box let's choose the ones that still bring us joy and let's put the rusty old ones away that either we don't like or aren't helping our body put them away and also choose choose the ones that are going to have the biggest size impact so for example we know that breakfast for those that have breakfast that counts 20% of our energy we know that snacks accounts for most people 25% of our energy intake these are um eating events that we generally do in isolation so they're not dependent on someone else around us these are really simple ways that we can improve our overall diet just changing our breakfast or just changing our snacks right and this will build on itself so it's food you eat food every day so if you can find some of these changes that so as as you mentioned earlier in our talk today you can't feel your blood cholesterol you can't feel your blood glucose on any given moment but if you have less of a fgy brain if you have more energy you're feeling more alert a lot of those are things that will be impacted by this and so as you play with some of these and you see that this modest change LED to you being clearer headed more articulate that's empowering and then you go on to the next one and the next one and the next one and it'll build so it's a very exciting time and this is what we ask people as well following The Zo program and on the method study we actually asked people how they felt now I've run over 30 randomized control clinical trials I never ask people how they feel I measure all of these measurements of cholesterol of glucose and what was amazing is people felt great so we know people on The Zo program feel great but actually putting it to the test in a proper randomized control Tru people had more energy they had better mood they felt more alert uhuh and I found that really quite empowering because always I've only been interested in these blood markers but actually seeing that people are feeling better and so then they're more likely to sustain these changes very exciting that is a brilliant way I think to wrap up because we started with this issue about sustainability and I feel like we've we've finished with sustainability I know that actually I could leave the room and you'd keep talking for scratched the surface so I re Sarah's like oh no there were 10 other things I want to talk about I'm afraid we're going have 100 other things we're going to have to stop now there are many more times we can do this in the future and I'm going to tryy and do uh a summary and we went into quite a few places so I'm going to uh going to do my best so I think the first thing was we started by saying basically the whole concept of dieting is broken because the concept of dieting is something you do for a short period of time and actually that doesn't work what you need to think about is what is the way I'm going to eat for the rest of my life and if I do that amazingly like no matter how old I am I can profoundly improve my health which I think is for me the number one message whenever I discuss this with with anyone it's like it's amazing the L of science says it doesn't matter what you've done before however old you are whatever you can make changes now that is going to improve your health which I just find is just really motivating to to do something the second thing you talked about which I hadn't heard before is Unapologetic deliciousness which is a bit hard to say but a brilliant idea it is a mouthful which is you know the food needs to be something you want to eat and that you can stick with you therefore need to avoid restriction any diet which says I'm getting rid of all of these things and this is going to be really hard you're not going to be able to sustain um so it needs to be something about adding in a lot of good things into your diet rather than about taking everything away I think very strong um agreement that people need to lower the amount of animal fat that they're eating if they're eating in anything like the typical Western diet being in the US or the UK or France wherever that might be um and as importantly we need to reduce the number of sort of poor quality carbohydrates atates and so that's anything where you're adding sugar to the food but also I think the thing that is less obvious for most people you know what you technically call refined grain so this is stuff where it's all been um it's no longer like the original seed or grain and it's become you know white flour in our bread or white rice which I was brought up to think was really healthy and that almost everyone agreed you want to have more fiber in your um in your diet um in part because of like all this new science about how this supports your good bacteria and has these positive impacts and I think Christopher you talked about like if I was going to make this really simple it was almost like two things so one was whole food and not processed and what you're explaining is that the processing does I think like two bad things one is it smashes all of this stuff up so that when you're eating like this processed um carbohydrate basically your body turns into blood sugar almost immediately and that caus is all of these problems that we we've talked about about over the last few days and can lead towards diabetes and whatever but also the processing tends to strip things out and basically you're you're removing lots of the healthiest bits uh and therefore whole food is sort of like before you've taken all the stuff away and you know you keep processing unfortunately is what we tend to get given a lot of and the other part is plantbased and you're very clear it doesn't mean you have to be vegan or you have to be vegetarian but you're moving towards a diet where um unlike really I guess what I grew up with which is like a big piece of meat in the middle and a little bit around the side suddenly you know if the meat is on the plate it's like a small bit on the side and it doesn't have to be in every meal either and then I think we were um Sarah was explaining when you think about plant as well you really want this diversity of plants because it's giving you all of these different fibers and Chris you're talking about one of your studies you know we and we see this as well all the different f I are supporting all the different bacteria so sort of whole food and plant-based is your um core and then we talked a little bit about don't be scared of fats many of us were brought up to be scared of fats but you know Sarah again she will talk for an hour about how good many healthy fats can be and it's really these are these sort of plant-based um fats and you talked about avocados and olives and olive oil and and nuts and so long and then I think towards the end we talked really about personalization the idea there isn't just like one size fits all you did this brilliant study called diet fits and it turned out you could you know go to these two extremes of like low fat or low carb and on each of them some people would do really well and some people would do really badly and and Sarah you talked about our own um study showing well it sort of makes sense because you can see like a 20-fold difference in how people's blood sugar responds and how people's blood fat responds so it sort of makes sense that there isn't just one answer for for everybody and I think we wrapped up by saying you know I think there is quite a lot of consensus therefore about um sort of key things that people should change there's also a lot of exciting new science coming which is early about new ways of thinking about eating and Sarah I think you mentioned for example Tim restricted eating when you eat sleeping all of these things um potentially having a lot of effect on your health and just starting to be studied and you know probably keep watching here because hopefully there'll be some exciting new studies that we can report back on in the future fantastic great wrapup great and foods to be enjoyed that's the most important and listeners be kind to yourself it's a journey enjoy the journey I think that's a brilliant way to wrap up thank you very much Christopher and Sarah thank you I hope that you learned a lot on today's show about the best and worst diet and about what to eat for your health now if listen to this episode has motivated you to change how you eat to improve your health then you may want to do what I do which is use Zoe's app every day for personalized advice and personalized support on how I can eat the best foods for me to learn more about how Zoe can help you to feel better now and live healthier in the years to come simply go to zoe.com podcast right now you can also get 10% off your membership as always I'm your host Jonathan wolf Zoe SCI and nutrition is produced by yell huin Martin Richard Willen and Tilly fford the Zoe science and nutrition podcast is not medical advice it's for General informational purposes only see you next time

Channel: ZOE

Views: 199,677

Keywords: zoe, zoe podcast, gut health, ultra processed foods, tim spector, jessie inchauspe, gut health diet, ultra processed foods documentary, ultra processed food

Id: WfPqlTRFnLU

Length: 62min 27sec (3747 seconds)

Published: Thu Jan 25 2024