What is the Best Fast Length? (Fasting Basics 3) | Jason Fung

hi welcome back i'm dr jason fung how long should you fast for what's the best fasting regimen that's the question we're going to cover and it's coming right up and i'm going to share the fasting regimen that ursula used at the end of this video so stay tuned [Music] when you're trying to fast they differ in two major ways one is what you're allowed to take during that fast and i covered that in the last video what breaks a fast in this video i'm going to cover how long you fast forward because that's the other major way that fats are different our body really is in one of two states it's either sort of storing energy like when we eat or it's burning its stores of energy because we need to we have no food available we have to take it back out so during fasting it's simply a transition it doesn't mean that there's anything unhealthy but it's a difference in terms of where we're getting our energy from so what are the different fasting regimens the standard regimen but we don't often think of it that way is three meals a day breakfast lunch and dinner with no snacks in between and this is what we took mostly in the 1960s and 1970s up until then snacks were very frowned upon and because it was not easy to keep a lot of food in the house and so on mostly we didn't eat in between meals and we didn't eat after dinner so if you were hungry after dinner your mom would usually say oh you should have ate more at dinner because there's nothing to eat until breakfast time and that's where the term came from the fasting period was from dinner one night so if you went had dinner at 7 00 p.m for example and didn't have breakfast until 7am that's a 12 hour fasting period that people had every day without thinking about it if you ate breakfast a little later perhaps 8 or 9 a.m you'd have somewhere around a 14-hour period of fasting and that provided a pretty good balance and kept people for the most part from getting obese as you can see because it's quite rare in the 60s and 70s that is the feeding period was 10 to 12 hours and during that period of time we're trying to store food energy store body fat and that's balanced almost every day with 12 to 14 hours of fasting that's where the english term breakfast comes from it's the meal that breaks your fast so the baseline fasting period should really be about 12 to 14 hours now if we're trying to lose weight specifically lose body fat we can simply extend that fasting period so instead of 12 to 14 hours of fasting we can go up to for example 16 hours of fasting this is a very popular regimen it's often called 16 8 which denotes 16 hours of fasting in an 8-hour feeding window so for example if you ate breakfast at 11 a.m and 8 until 7 pm well that's an 8 hour period of time during which you can eat your meals and outside of that the other 16 hours you're going to fast so that's a 16 8. sometimes this is also referred to as time restricted eating because you're restricting your feeding to a certain window of time we can take this idea even further and we can go down to a single meal a day for example so instead of fasting for 16 hours we would extend that and only have one meal perhaps dinner for example so if you go from dinner one day until dinner the next day it's about a 23 to 24 hour period of fasting you're still eating every day in a 24 hour fast and because of this some people refer to this as one meal a day also sometimes called omad or omad and this is a very successful strategy for some people and also a very popular strategy which we'll get into later another variation on time restricted eating or omad is what's called the five to two diet and this was popularized by dr michael mosley and the idea is that for five days you would eat normally and for two days you would limit the number of calories that you eat to 500. strictly speaking it's not fasting because you're still taking 500 calories in that day but during that day that 500 calories represents much less than most people take so it could be thought of as a fasting day those those meat those calories can be taken all at once or it could be broken into three meals it doesn't specify but as i mentioned in the previous video even taking small amounts of calories it doesn't negate all the benefits of fasting because insulin is still going to fall you're still going to be dipping into your stores of body fat in order to provide the energy that you need so five to two is another dietary strategy that some people have found very successful once we go past the 24 hours of fasting it gets into a group of fast that i call extended fasting because now you're going past a full day of fasting so you're no longer eating every day if you go to 36 hours of fasting for example if on monday you eat dinner at 7 pm for example and on tuesday you don't eat at all and don't eat until wednesday at 7 00 am you've got a 36 hour period of fasting and on that tuesday you wouldn't have eaten at all this is a very powerful strategy because it it increases the period of time that your body relies on body fat by skipping that one meal that you get with the 24 24-hour strategy you're able to link that directly to your sleeping period where you get almost eight hours of fasting almost for free because you're not even aware of that so you have two sleeping periods which make up a lot of time of fasting and keeping your body in that fat burning state because your body has nothing else to rely on and you can take this idea even further so you don't have to limit yourself to 36 hours you can go to 42 hours or you can go to multiple day fast keep in mind that the longer fast you do the more powerful it is however there's also the potential that you're not going to feel well or you're going to run into other troubles if you are taking medications for example so it's a double-edged sword and make sure if you're especially if you're on medication that you do check with your doctor beforehand but there's really no upper limit to the number of days you can fast in the 60s is very popular to do 30 days 60 days the world record is more than 380 days of fasting so you could actually keep going some people actually like the extended fast because after day two the hunger actually starts to dissipate people get used to feeling in that state and find it pretty normal and so they're able to lose a lot of weight in a short period of time the question i hear all the time is what's the best fast there's not really one they all have advantages and disadvantages so the shorter fasts are easier to do but they're less powerful the longer fasts are a bit harder but you see results very quickly the most popular fast actually are the shorter fast done a little bit more frequently so the 16 8 and the 24 hour fast are the most popular and there's a good reason for this it's important to make sure that you're able to fit the fasting into your lifestyle so if you do a 16-8 schedule for example by skipping breakfast well that's easy because nobody really minds if you just have a coffee at breakfast time if you do one meal a day and you just have a coffee at breakfast and you work through lunch again nobody minds it doesn't really matter so much as you start to get into the 36 hour fast now you're missing dinner time which is the most social meal in most western lifestyles it's often one where you're taking with friends where you're taking with family or you're sitting down at a meal together to share how you did during the day so it becomes a little awkward as you start to get into those longer fast and when it becomes difficult to fit it in to your daily schedule your life schedule well the harder it's going to be to keep it going so therefore what works well for most people is the 16-8 fast and also the one meal a day fast oftentimes there's there's periods where it's easy to put in a longer fast and there's no reason why you couldn't slip one of those longer fast in for example if you find that your spouse is away on a business trip or you're alone for a few days and you have a lot of work to do for example well you could easily slot them in but it might not be something that you do week in and week out but here's the key make sure that it's something that you can fit into your lifestyle remember that you're trying to fit the fasting into your lifestyle you're not trying to fit the lifestyle into your fasting ursula was thin as a child but after she had her kids she started to gain weight in her mid-30s she couldn't help it and eventually she was diagnosed with a disease called polycystic ovary syndrome to lose weight she even tried a gastric bypass surgery commonly called stomach stapling and she was able to lose a lot of weight but unfortunately life happened and it all came back as this often happened with surgery she was struggling for a while until she started to listen to some of the podcasts that i had been putting out as well as looking at the obesity code and started fasting she became frustrated and fasting during the week weeknights became easy for her as the weekends much more difficult because she ate with her family so she started to use 20-hour fasting or a four hour eating window during that time she found it easy she took a little bit of salt and water a lot of black coffee and she found that if she was busy it didn't really bother her too much and because of that she is able to lose all her weight she is back in control of her health and feeling better than ever once in a while she adds in a 48-hour fast whenever her life schedule allows she's still working up to longer ones but i have no doubt she'll be very successful that's it for this week thanks for watching everybody and if you learned something do me a favor hit that like button you know the one that looks like this you know the one i'll see you next week take care

Channel: Jason Fung

Views: 513,346

Rating: 4.9766002 out of 5

Keywords: best fast length, fast, best fast, fasting length, how long to fast, best intermittent fast, jason fung, dr jason fung, best length of time to fast, best fast lenght for weight loss, best lenght of time to fast, best length of tiem to fast, best lenght of tiem to fast, intermittent fasting, fasting, weight loss, nutrition, Health, intermittent fasting benefits, fasting tips, intermittent fasting tips

Id: 1ZH_2cKbqzM

Length: 12min 3sec (723 seconds)

Published: Sun Jan 31 2021

Reddit Comments

[u/Gangreless]

I'm generally a big fan of Dr. Fung but this video is really irresponsible specifically for how casually he encourages very long (30, 60, ++ days) fasts, including citing the world record Barbieri case which nobody should be looking at emulating, and then says

so there's really no upper limit to how long you can [extended] fast

No mention to needing a good store of excess body fat to sustain that, no mention of keeping up electrolytes or the dangers of refeeding syndrome after such a long fast. This is how people end up in the hospital, they see a popular video, hear something like and decide to jump straight into the deep end with little to no other research.