禁食与限时进食对减脂和健康的影响

安德鲁·休伯曼：

Welcome to the Huberman Lab 播客, where 我们 discuss science 和 science-based tools 对于 everyday life.

安德鲁·休伯曼：

I'm Andrew Huberman 和 I'm a professor of 神经生物学 和 ophthalmology at Stanford School of Medicine. Today 我们're talking all 关于 fasting, 和 anytime 我们're talking 关于 fasting, 我们 are also talking 关于 eating 因为 我们 all need to eat sooner 或 later. 我们're going to talk 关于 how fasting 和 when 我们 eat influences a large range of aspects of 我们的 health 和 wellbeing, both physical 和 mental. So, well nowadays, most 人们 are familiar 与 the term intermittent fasting, also sometimes called time-restricted feeding. I think most 人们 don't 确实 understand how 那 process works. It's sort of obvious 那 intermittent fasting, aka time-restricted feeding, involves eating at certain periods of each 24-小时 cycle 或 maybe even not eating 对于 entire 天 in some cases. 但 if 你 think 关于 it, everybody sleeps eventually, 和 因此 因为 人们 don't eat 期间 their sleep, almost everybody is employing some form of intermittent fasting 或 time-restricted feeding.

安德鲁·休伯曼：

What 我们're going to talk 关于 today is how particular schedules of time-restricted feeding 可以 impact 我们的 health in 不同的 ways. 和 when I say 不同的 ways, I mean 我们 are going to talk 关于 how intermittent fasting, aka time-restricted feeding, impacts weight loss, fat loss in particular, 肌肉 maintenance 和 loss 和 gain, organ health such as gut health 和 liver health, the genome, the epigenome, 炎症, sickness, 恢复 和 healing 从 sickness, 运动, cognition, 情绪, 和 lifespan. So 我们're going to cover a tremendous amount of information. I promise to make it all directly accessible, regardless of whether 或 not 你 have a background in biology 和 metabolic science 或 not.

安德鲁·休伯曼：

I'm also going to talk 关于 a lot of tools. In fact, I'm going to discuss a number of tools 期间 today's episode 那 actually make it such 那 你 don't have to follow any feeding schedule 或 fasting schedule, same thing if 你 think 关于 it, in any absolutely strict, regimented way. Meaning if 你 were to only eat 期间 an eight-小时 period of each 天 most of the time, 但 then occasionally eat across a 12-小时 period of the 天, in theory, 那 could actually have pretty serious detrimental health effects, 和 yet there are things 那 你 可以 do to attenuate 那些 negative effects. In fact, there are things 那 你 可以 do 和 或 take 那 可以 make it as if 你 did not eat at all. 和 so 我们'll discuss what 那些 tools are. 和 in many cases, 对于 sake of health, weight loss 和 表现, making the 身体 think 那 it did not eat at all 可以 actually be quite beneficial. Today 我们're going to cover mechanism 和 我们're going to cover tools. 之前 我们 do 那, I want to highlight a particular result 那 was published recently 因为 it serves as a useful backbone as 我们 wade 进入 the conversation 关于 fasting.

安德鲁·休伯曼：

这 is a 研究 那 was published in the journal, "Cell 代谢," a Cell Press Journal, excellent journal, 和 the title of the paper is Fasting 血液 Glucose as a Predictor of Mortality: Lost in Translation. 和 I'll explain what the lost in translation part means in a moment. 但 the basic takeaway of 这 研究, 和 I 应该 mention 那 the 首先 author of 这 研究 is Palliyaguru, P A L L I Y A G U R U, guru. Palliyaguru et al. The basic finding of the 研究 is 那 in humans, higher 血液 glucose is associated 与 mortality. 和 in fact, if 你 look at 血液 glucose, resting 血液 glucose across the lifespan, what 你 find is as 人们 age, resting 血液 glucose goes up. Now 这 is 非常 interesting 因为 对于 a long time it was thought 那 代谢 actually goes down as 我们 age, 和 to some extent 那's true, 但 the reductions in 代谢 are not nearly as robust as 我们 once thought 那 they were across the lifespan.

安德鲁·休伯曼：

然而, unless there's something done to mitigate the 增加 in 血液 glucose associated 与 the aging, almost everybody experiences a gradual 但 regular 增加 in resting 血液 glucose 那 predicts mortality. Now, the title, as I mentioned, is "Fasting 血液 Glucose as a Predictor of Mortality: Lost in Translation." 和 the reason 那 they included "lost in translation" in the title is 那, what I just told 你, 那 增加 in resting 血液 glucose predict mortality, 或 are correlated 与 mortality, is true 对于 human beings 和 对于 nonhuman primates, monkeys. 但 the opposite is true in mice. 和 so I thought it was 重要 to use 这 研究 as an example of where 研究 in mice 经常, 但 not 总是, translate to humans 和 to nonhuman primates.

安德鲁·休伯曼：

So today I'm going to be careful to distinguish when a 研究 was performed in mice versus in humans 因为 it seems 那 at least when discussing feeding, 血液 glucose, 和 other aspects of diet as they relate to health 和 wellbeing, whether 或 not a 研究 was performed in rodents 或 in humans 可以 be 非常 重要. In 这 case, the 结果 were directly 180 degrees opposite to 一 another. In other words, in mice, resting 血液 glucose went down 和 was associated 与 mortality, so lower 血液 glucose associated 与 mortality, whereas in humans, higher resting 血液 glucose was associated 与 mortality. 和 obviously what 我们're mostly interested in is health 和 wellbeing of ourselves, of humans. I'm sure there are some 人们 out there 那 are intensely concerned 关于 the health 和 wellbeing of mice, which 你 could imagine a few rare contexts where 那's 重要. 但 obviously most of us are interested in human health. So I'll be sure to emphasize when 研究 were performed in humans versus in mice.

安德鲁·休伯曼：

之前 我们 begin, I'd like to emphasize 那 这 podcast is separate 从 my teaching 和 研究 roles at Stanford. It is 然而 part of my desire 和 effort to bring zero-cost-to-consumer information 关于 science 和 science-related tools to the general public. In keeping 与 那 theme, I'd like to thank the sponsors of today's podcast.

安德鲁·休伯曼：

Okay, so let's talk 关于 feeding, fasting, 健康与表现. 和 I want to just establish a few foundational terms so 那 我们're all on the same page. 首先 of all, rather than talk 关于 fasting 或 time-restricted feeding, I'm largely going to talk 关于 time-restricted feeding, 但 please understand 那 time-restricted feeding is just 一 side of the coin, 那 is a 二-sided coin 那 includes fasting, on the 一 hand, not eating, 和 time-restricted feeding on the other hand.

安德鲁·休伯曼：

I may occasionally say fasting, 但 因为 fasting 和 eating establish 不同的 biological conditions in the 身体, time-restricted feeding is the term 那 I 会 use to describe the overall plan of restricting 一's eating window, as it's called, to a particular phase of each 24-小时 天, 或 in some cases to particular 天 within the 周, 因为 as 你'll soon learn, there are aspects of time-restricted feeding, aka fasting, 那 involve eating every other 天 或 eating 一 way 对于 five 天 和 then fasting 对于 二 天 和 so forth. So I'll be 非常 precise 关于 what I mean 和 why I mean it, 但 对于 the time being, I'm going to refer to time-restricted feeding as a way to put an umbrella over 这 conversation.

安德鲁·休伯曼：

秒 of all, I am going to emphasize a lot of biological mechanism. If 你've listened to 这 podcast 之前, 你 know 那 I 总是 begin 与 biological mechanism. I do describe tools of how to implement 那些 mechanisms, 但 I wholeheartedly believe 那 knowing mechanisms 和 understanding how 这些 processes work gives 你 tremendous flexibility 和 understanding 和 control over the processes of 你的 mental 和 身体健康.

安德鲁·休伯曼：

Whereas if I were to just list off a menu of things to do 和 not to do, 那些 会 work. 但 那些 会 not give 你 the kind of understanding 那 会 allow 你 to navigate 通过 life, 通过 travel, 通过 dinners out, 通过 不同的 运动 schedules, whether 或 not 你're 一 age 或 another age, male, female, etcetera. I'm giving 你 mechanisms so 那 你 可以 gain 更多 control over the 系统 in 你的 大脑和身体. Everything's timestamped. So if 你 want to jump to the to-dos, 你 可以 certainly do 那, 但 I encourage 你 to hang in there 对于 the mechanism bit. I 会 make it all 非常 clear 因为 if 你 understand mechanism, 你 are in a true place of power 和 control over 你的 biology.

安德鲁·休伯曼：

If ever there was a topic 那 is controversial, 尤其是 on the internet, it is 那 of diet 和 nutrition. So I'm wading 进入 这 与 a smile 和 in eager anticipation of all the 但, 但, 但 这 和 但, 但 那 和 wait -- 但 这 showed 那.

安德鲁·休伯曼：

Here's the deal. 我们 need to precisely define what it is 那 我们're talking 关于 when 我们 talk 关于 nutrition. I'm going to give 你 an example of a 研究 那 was published a few years ago, 2018, by a colleague of mine at Stanford. Chris Gardner is a terrific professor of nutrition 和 has done a lot of 重要 研究 on how nutrition impacts 不同的 aspects of health. 这 is a large scale 研究. It was published in "JAMA," the journal of the American Medical Association, 一 of the 非常 top tier journals in the area of medicine, 和 certainly 对于 a paper on nutrition to show up there meant 那 it had to meet an exceedingly high standard. 这 paper where Chris is the 首先 author, its Gardener et al., 2018, "JAMA," looked at weight loss in 人们 following 一 particular diet versus another particular diet. 和 这 was a 12-month weight loss 研究. So it was focused specifically on weight loss, 尽管 they looked at some other parameters as well. 和 the basic conclusion of the 研究 was 那 there was no significant difference in weight change between 人们 following a healthy low fat diet versus a healthy low carbohydrate diet 与 significantly 更多 dietary fats in them.

安德鲁·休伯曼：

这 caused a lot of ripples in the world of nutrition 和 nutritional science 和 certainly in the general population, 因为 anyone 那 understands diet 和 nutrition 会 immediately say, "但 wait, there are all sorts of 不同的 implications of eating 一 type of diet, say low carbohydrate, higher fats, versus a higher carbohydrate, lower fat diet." 和 indeed there are. 这 研究 was focused specifically on fat loss 和 on weight loss. So as 我们 discuss time-restricted feeding, 我们 need to be 非常 precise 关于 what are the effects of time-restricted feeding 和 of eating in particular ways at particular times. 我们 are going to emphasize again whether 或 not the 研究 was done in mice 或 in humans, in athletes, in men, in women, 或 both.

安德鲁·休伯曼：

但 the 研究 从 Gardner 和 colleagues is a beautiful 研究 和 确实 emphasizes 那 if 一's main goal is simply to lose weight, then it 确实 does not matter what 一 eats, provided 那 the number of calories burned is higher than the number of calories ingested. 然而, anyone out there who understands a little bit of biology, 或 a lot of biology, 会 agree 那 there are many factors 那 impact 那 calories burn part of the equation. Some of 那些 are obvious. So 对于 instance, amount of 运动, type of 运动, basal metabolic rate, how much 能量 一 burns just sitting there. I've talked 之前 on 这 podcast 关于 neat nonexercise-induced thermogenesis where if 人们 bounce 大约 a lot 和 fidget a lot, they 可以 burn anywhere 从 800 to 2000 calories per 天.

安德鲁·休伯曼：

So their basal metabolic rate is actually much higher simply 因为 they're fidgeters, whereas 人们 who tend to be 更多 stationary have a lower basal metabolic rate on average. There's great science to support 这. Metabolic factors 和 激素 are also 非常 重要. 激素 such as thyroid 激素 和 insulin 和 growth 激素 和 the sex story to 激素, testosterone 和 estrogen, 那些 水平 会 also profoundly influence the calories out. The calories, a burn component of the calories in calories-out equation. So if out there on the internet 或 in listening to a particular podcast 或 speaker, somebody says, 这 is the ideal diet, 或 calories in, calories out does not matter, 或 calories in, calories out is the only thing 那 matters. I think it's 非常 重要 to understand 那 there are some foundational truths such as calories, in calories out, 但 那 of course 激素 factors 和 the context in which a given diet regimen is taking place are exceedingly 重要.

安德鲁·休伯曼：

A good example of 这 会 be puberty. At 那 time in life, sex steroid 激素 are changing profoundly in the 身体 as are growth 激素 和 other 激素. 和 much of caloric intake is directed towards protein synthesis, towards the production of 肌肉 和 bone 和 other 组织 of the 身体. 和 那's 因为 of changes in 激素 那 我们 call puberty. So there's no way 那 我们 可以 drill 进入 every aspect of a given feeding plan 或 feeding schedule 那 会 allow us to tap 进入 every aspect of the list 那 I read out 之前, weight loss, fat loss, 肌肉, organ, genome, epigenome, 炎症, 运动, cognition, 情绪, 和 lifespan. 但 today 我们're going to be 非常 precise 关于 how time-restricted feeding, it's 非常 clear 从 both animal 研究 和 human 研究, 可以 have a 非常 powerful 和 positive impact on everything 从 weight loss 和 fat loss to various health parameters.

安德鲁·休伯曼：

这 is a beautiful literature 那's emerged mostly in the last ten 或 15 years, 和 as 我们 march 进入 这 literature, what 你'll see is 那 there actually is a perfect diet 对于 你 on a given 天, 和 那 perfect diet 对于 你 on a given 天 is contextual, meaning it depends on what 你 did yesterday 和 what 你're going to do tomorrow. So there is a perfect diet 对于 你, 和 today I'm going to arm 你 与 the mechanisms 和 understanding 那 会 allow 你 to define what 那 perfect diet is, 和 会 allow 你 to eat on a schedule 和 to eat the things 那 are going to best serve 你的 goals.

安德鲁·休伯曼：

So let's talk 关于 eating 和 what happens when 你 eat, 和 let's talk 关于 fasting 或 not eating 和 what happens when 你 fast. I did an entire episode on eating 和 代谢 和 激素 和 other factors 那 impact appetite. 我们 don't have time to go 进入 all 那些 details now, 尽管 你're welcome to listen to 那 episode as well. 但 我们 可以 briefly describe the overall conditions 那 are set in the 身体 when 我们 eat 和 when 我们 don't eat. The keyword here is conditions. If I 可以 emphasize anything today, it's 那 what 你 eat 和 when 你 eat it set conditions in 你的 身体, 和 那些 conditions 可以 be 非常 good 对于 你 或 非常 bad 对于 你, depending on when 你 eat. In fact, when 你 eat is as 重要 as what 你 eat. I'll repeat 那. When 你 eat is as 重要 as what 你 eat, at least as it relates to health parameters in particular, liver health 和 心理健康.

安德鲁·休伯曼：

Some simple rules 关于 eating. 首先 of all, when 你 eat, 通常 你的 血液 glucose, 你的 血液 sugar, 会 go up. Also, insulin 水平 会 go up. Insulin is a 激素 那's involved in mobilizing glucose 从 the bloodstream. How much 你的 glucose 和 insulin go up depends on what 你 eat 和 how much 你 eat. In general, simple sugars, including fructose 从 fruit 但 also sucrose 和 glucose, 和 simple sugars 会 raise 你的 insulin 和 血液 glucose 更多 than complex carbohydrates, things like grains 和 breads 和 pastas 和 so forth. 和 grains 和 breads 和 pastas 和 so forth 会 raise 你的 血液 glucose 更多 than fibrous carbohydrates like lettuce 和 broccoli 和 things of 那 sort. Protein has a somewhat moderate 或 modest impact on insulin 和 glucose 和 fat has the lowest impact on raising 你的 血液 glucose 和 血液 insulin. So what 你 eat 会 impact how steep a rise in 血液 glucose 和 insulin takes place. 和 there are a number of factors 那 are related to 你的 individual health 那 会 also dictate how steep 和 how high 那 rise in glucose 和 insulin 会 be.

安德鲁·休伯曼：

对于 the time being I'm leaving out 人们 who have type 1 diabetes. 这些 are 人们 那 don't manufacture their own insulin. 和 type 2 diabetes is 本质上 insulin insensitivity, lack of sensitivity to insulin, which leads to high 血液 glucose. 但 when 你 eat, 血液 glucose goes up 和 when 你 don't eat, 血液 glucose 和 insulin go down. The longer it's been since 你的 last meal, the lower 通常 你的 血液 glucose 和 insulin 会 be. 和 the higher things like GLP-1, glucagon-like peptide 1, glucagon being a 激素, 那's also secreted when 你 are in a fasted state, 或 a low 血液 glucose state. It's involved in mobilizing various 能量 sources 从 the 身体, including fat 通过 what 我们 call lipolysis, also using carbohydrates 和 potentially even using 肌肉 as a source of 能量. So 那's kind of a fire hose of information 关于 what happens when 你 eat 和 don't eat, 但 just think of it 这 way, 血液 sugar 和 insulin go up when 你 eat. They go down when 你 don't eat. 和 other 激素 go up when 你 don't eat.

安德鲁·休伯曼：

So there are 激素 associated 与 the fasted state 和 there are 激素 associated 与 the eating 和 having-just-eaten state. Now, the most 重要 thing to understand is 那 like everything in biology, 这 is a process 那 takes time. So insulin 和 glucose go up when 我们 eat, 和 it takes some period of time 对于 them to go down. Even if 我们 stop eating, they 会 remain up 对于 some period of time 和 then go back down. It takes time. 这 is 非常 重要, 因为 if 你 look at the scientific literature on fasting, on time-restricted feeding, it's absolutely clear 那 the health benefits, not just the weight loss benefits, 但 那 the health benefits 从 time-restricted feeding, occur 因为 certain conditions are met in the 大脑和身体 对于 a certain amount of time. 和 那 gives us an anchor 从 which to view what eating is, in terms of how it sets conditions in the 身体 over time.

安德鲁·休伯曼：

和 if 那 sounds overly analytic, I promise 你 这 is the simplest 和 best way to think 关于 any eating schedule 或 any eating plan. So I think it's fair to say 那 in the field of nutrition, there are a few landmark 研究 那 serve as 确实 strong anchors 对于 building 我们的 understanding of what to eat 和 what not to eat 和 when to eat, depending on 我们的 goals. The Gardner 研究 那 I mentioned earlier is 一 such 研究 in 那 it says if 你的 goal is weight loss, it 确实 does not matter what foods 你 consume, provided 那 你 consume a sub-maintenance caloric diet. 然而, I want to emphasize again, 那 sets aside issues of adherence, meaning how easy 或 hard it is to adhere to a given diet.

安德鲁·休伯曼：

Some 人们 find it much easier to follow a high fat, low carbohydrate diet. Some 人们 follow a 不同的 diet 因为 it's much easier 对于 them to follow. 和 some 人们 are concerned 与 心理表现 和 athletic 表现. So, 那 研究 doesn't say there's a best diet. What it says is 那 what 你 consume is 更少 重要 than the amount of food 那 你 consume, at least 对于 sake of weight loss, not necessarily 对于 sake of health.

安德鲁·休伯曼：

Now, the 研究 那 I'm going to refer to next is what I 会 consider the 秒 major pillar of nutritional 研究. 这 is a truly landmark 研究 那 was carried out by Satchin Panda, who is a professor at the Salk Institute 对于 Biological 研究 in San Diego, an absolutely phenomenal institution, 和 an absolutely phenomenal researcher. I've known Satchin 对于 a number of years 和 I want to emphasize 那 the current literature on intermittent fasting 和 time-restricted feeding 可以 largely be attributed to Satchin 和 the work 那 he's done.

安德鲁·休伯曼：

There are others involved too, of course, 和 of course, time-restricted feeding 和 fasting has a rich history 那 goes back many hundreds, if not thousands of years in 不同的 cultures 和 religions. 但 the science of time-restricted feeding 可以 确实 mainly be attributed to the incredible work 那 Satchin has done. 和 I'm grateful to consider him a friend 和 a colleague, 和 我们 consulted at length in anticipation of 这 episode. I also hope to have him on as a guest in the future.

安德鲁·休伯曼：

The landmark paper 那 came 从 Satchin's lab was published in 2012. 这 was a paper in mice 那 set the basis 对于 研究 in humans 那 came later. 和 the title of 这 paper is "Time restricted feeding 没有 减少 caloric intake prevents metabolic diseases in mice fed a high fat diet." So the title tells us a lot. It says 那 what's varied in 这 研究 is not what 这些 mice ate, it was when they ate it. 和 there were 本质上 four conditions in 这 研究 和 the 结果 are absolutely remarkable.

安德鲁·休伯曼：

So I'm going to walk 你 通过 the major 结果. What they did is they gave mice access to 不同的 types of food. There were four groups. 一 group of mice had access to just a normal mouse diet. It 会 not be a diet 那 你'd be 非常 interested in. I confess, I've actually tasted mouse chow. If 你 work 与 mice at all, 你 just have to do it at least once. It doesn't taste 非常 good. It tastes like a 非常 bland graham cracker cookie, 和 I confess 那 I only had the tiniest little bit. 但 mice like 那 stuff, 和 if 你 allow them to eat 那 stuff, what's called "ad libitum," whenever they want, 你 just keep it in their food 24 小时 a 天, they 会 eat sometimes 和 then they won't eat it at other times. 或 in 这 case, they also had a condition where they gave them mouse chow in a time-restricted way, just 对于 a certain number of 小时 each 天, 关于 eight 小时.

安德鲁·休伯曼：

或 they gave them a high fat diet 那 was a separate group, got a high fat diet at any time they wanted. So 这 was kind of the carnival 对于 mice, 因为 mice 确实 like high fat, highly palatable foods, 和 so they got a lot of goodies 和 high fat in their food. 和 then there was a fourth group 那 had access to the high fat diet as much as they wanted to eat, 但 only 期间 a restricted time period of each 24-小时 cycle. Now, mice are nocturnal, humans are what 我们 call diurnal. Actually, 我们're not 确实 diurnal, 我们're crepuscular, which means 那 我们're most active in the 早晨 和 in the 晚上, not so much in the 下午. 但 nonetheless, everything I'm going to tell 你 is true also 对于 humans. 和 我们 know 这 now 从 human 研究.

安德鲁·休伯曼：

一 of the most 重要 things to take away 从 这 研究 was 那 mice 那 ate a highly palatable, high fat diet, a great tasting diet, 但 only 期间 a restricted feeding window of each 24-小时 cycle, maintained 或 lost weight over time. Whereas mice 那 ingested the same diet, same amount of calories, 但 had access to 那些 calories 大约 the clock, gained weight, became obese 和 quite sick. 和 as an additional 秒 point, the mice 那 restricted their feeding window to a particular portion of eight 小时 of every 24-小时 cycle, actually showed some improvement in 重要 health markers. 和 what was even 更多 incredible is 那 mice 那 only ate 期间 a particular feeding window also experienced some reversal of some prior negative health effects.

安德鲁·休伯曼：

So 这 研究 确实 lit up the world 和 got 人们 excited 关于 time-restricted eating. Again, they used an eight-小时 feeding window. The story 大约 那 eight-小时 feeding window is kind of interesting though. Not many 人们 know 这 因为 it wasn't included in the paper 和 there was no reason to include it in the paper, not to out anybody, 但 it turns out 那 the reason they used an eight-小时 feeding window 和 not a nine-小时 或 a 10-小时 feeding window is 因为 研究 of 这 sort are actually quite demanding to perform 和 require the constant presence of the graduate student 或 postdoc there to ensure 那 the food is in the cages at particular times 和 not in the cages at other times, 和 mice are 确实 good at hiding food. They'll even hide food in their jowls. 和 so there's a lot of work 那 has to be done to prepare 对于 那 eight-小时 feeding window 和 to make sure 之后 那 eight-小时 feeding window, there's all the food has been removed 从 the cage 和 从 the jowls of the mice 和 so forth.

安德鲁·休伯曼：

和 it turns out 那 the significant other of the graduate student 和 或 postdoc, I won't reveal who they were, running 这 研究 forbid their significant other, the scientist, 从 being in the lab 对于 periods of time 那 were much longer than the 10 或 12 小时 那 were required in order to ensure 这 eight-小时 feeding window. So when 我们 hear the eight-小时 feeding windows are holy, they are not holy, 和 later 我们 are going to talk 关于 how eating 对于 a time 那's restricted to eight 小时 versus 10 小时 versus 12 小时, 对于 instance, how 那 impacts various parameters like health parameters 和 weight loss, etcetera. 但 the eight-小时 feeding window was actually created 因为 of a real-world constraint on the 研究 和 the relationship of the researcher performing the 研究, not 因为 there's anything holy 关于 an eight-小时 feeding window.

安德鲁·休伯曼：

Now, an 重要 point 关于 when the feeding window falls within the 24-小时 cycle. It is 非常 重要 那 the feeding window fall 期间 the 更多 active phase of 一's 天. So 对于 humans, 那's 通常 in the early part of the 天 或 the later part of the 天, 但 not at 夜间. Put 非常 simply, there are a lot of 数据 now pointing to the fact 那 eating 期间 the nocturnal phase of the 24-小时 cycle is 非常 detrimental to 一's health.

安德鲁·休伯曼：

In fact, when 我们 eat 可以 either 增强 我们的 health 或 可以 diminish 我们的 health. When 我们 see light 可以 增强 我们的 feelings of wellbeing 或 可以 diminish 我们的 feelings of wellbeing. I've talked many times 之前 关于 这 on the Huberman Lab 播客 那 期间 the daytime 你 want to get as much sunlight 和 other types of bright light in 你的 eyes as is safely 可能, 和 then 你 want to avoid light in the middle of the 夜间. It has detrimental 多巴胺-lowering effects, 可以 cause depression, cortisol 增加, etcetera. So when 你 view light is as 重要 as the light 那 你 view. 和 when 你 eat is as 重要 as what 你 eat.

安德鲁·休伯曼：

In 这 研究, they saw something 确实 interesting, which was 那 not only did restricting food to a particular phase of the 24-小时 cycle benefit things like lean 身体 mass 和 fat loss, 和 a number of health parameters 那 I'll talk 关于 in a moment, 但 it also anchored all the gene 系统 of the 身体 和 provided a 更多 regular, stable, so-called 昼夜节律 或 24-小时 rhythm. 你 may be surprised to learn 那 80%, 80% of the genes in 你的 身体 和 大脑 are on a 24-小时 schedule. 那 is, they change their 水平 going 从 high to low 和 back to high again across the 24-小时 cycle. 和 when 那些 genes are high at the appropriate times 和 low at the appropriate times, meaning their expression is high 和 low at the appropriate times, 和 因此 the proper RNAs 和 proteins are made, 因为 DNA encodes 对于 RNA. RNA is translated 进入 proteins. When 那 happens, 你的 health benefits. When 那些 genes are not expressed at the right times, when they're high 或 low at the wrong times of each 24-小时 cycle, 那's when 你 get negative health effects. 这 研究 showed 那 when mice restrict their eating to an eight-小时 period within the most active phase of their 24-小时 cycle, many of the genes 那 are associated 与 这些 so-called circadian clocks, 这些 genes have names like PER-B-MAL-CRY1, etcetera, 那些 so-called clock chains.

安德鲁·休伯曼：

... CRY1, etcetera. 那些 so-called clock genes underwent a 非常 regular entrainment, a locking in to the proper 24-小时 schedule. 和 while 这 was in mice, 我们 now know 那 这 also occurs in humans.

安德鲁·休伯曼：

I've said 之前 on 这 podcast, 和 I'll say it again, 那 light, 和 when 我们 view light, is the primary way in which 这些 genes in the clock 系统 of 我们的 身体 get organized 或 entrained, meaning matched to the outside light-dark cycle. So viewing light early in the 天 和 in the 下午, 和 as much as 可能 all 天, great. Ideally, 那's sunlight. Avoiding light in the middle of the 夜间 is also great. It's great 因为 it causes the 增加 in particular genes 和 the 降低 in particular genes in every cell throughout 你的 身体 at the appropriate times.

安德鲁·休伯曼：

The 秒 most powerful timekeeper, 或 zeitgeber as it's called, is food 和 when 你 eat. In 这 研究, the 结果 they saw underscore 这 point. What they saw is 那 the peaks in 这些 clock genes became 非常 regular 和 the dips in 这些 clock genes became 非常 regular. 和 那 led to a whole host of 确实 重要 positive health effects. Conversely, when mice ate whenever they wanted across the 24-小时 cycle, 这些 clock genes became 确实 out of whack. The negative health consequences were the downstream result of 这些 changes in 这些 clock genes.

安德鲁·休伯曼：

这 has now also been shown to be true 对于 humans. So if 你 want to be healthy, 你 want 你的 organ health, 你的 metabolic health, to be entrained properly, 一 of the most 重要 things 你 可以 do is to view light at the appropriate times of each 24-小时 schedule 和 to not view light at other times of 那 schedule, 和 to eat at the appropriate time of each 24-小时 天.

安德鲁·休伯曼：

Now, again, there are rare instances 那 我们 会 discuss, when skipping entire 天 或 entire 24-小时 cycles of eating 可以 be beneficial. 但 对于 now 我们're talking 关于 schedules of time-restricted feeding 那 involve a window of feeding 那 falls 期间 你的 更多 active phase, so 期间 the daytime, putting aside 人们 那 work shift work, is when 你 want to eat. 和 这 eight-小时 feeding window provided a 非常 strong reinforcing signal 那 combines 与 light to ensure 那 这些 genes are expressed at the appropriate times. The short takeaway 从 这 is 你 probably want to think 关于, 和 perhaps even engage in, time-restricted feeding.

安德鲁·休伯曼：

So as I mentioned earlier, when mice 可以 eat 大约 the clock, bad things happen. 和 一 of the bad things 那 happens is 那 the liver suffers. The liver is involved in all sorts of things, production of 重要 激素 和 other factors related to 代谢. 和 when mice 可以 eat 大约 the clock, their livers got 非常 sick, fatty deposits in the liver, other factors in the liver, 本质上 taking them down the 通路 of liver disease.

安德鲁·休伯曼：

The time-restricted feeding 本质上 reversed 那 或 led, in many cases, to even healthier liver conditions. 和 那's based on 这 研究, 但 also additional 研究 also now in humans. So restricting 你的 feeding to a particular window every 24-小时 cycle has clearly been shown now, in mice 和 in humans, to 增强 liver health, which is wonderful.

安德鲁·休伯曼：

How does it do 这? Well, it happens 因为 food intake, as I mentioned earlier, sets certain conditions in the 身体 那 last 对于 a period of time. Anytime 我们 eat, whether 或 not 我们 are a mouse 或 a human, there's a period of time 那's required 对于 so-called digestion, 但 also gastric emptying 和 other processes related to breaking down 那 food 和 utilizing it. 和 那 is an active process. It requires 能量. 那 process of breaking down food involves certain cellular functions, 那 if they're ongoing throughout the 24-小时 cycle 或 even extended too far across the 24-小时 cycle, meaning 你're eating across a 14- 或 a 16-小时 或 an 18-小时 window; 那 causes serious problems.

安德鲁·休伯曼：

这 has now been established 因为 of the fact 那 it 增加 the expression of 不同的 proteins 和 genes in the 身体, such as TNF alpha, IL-6, IL-1. What are all 那些 things? They are pro-炎症性的 markers. So the reason 那 the liver gets sick when 你're eating too 经常 is 因为 炎症性的 markers are 增加了.

安德鲁·休伯曼：

这些 炎症性的 markers are not inherently bad. They're there 对于 a reason. 但 they are there in order to respond to certain challenges, 免疫 challenges 或 the ingestion of food 和 the breakdown of food. 但 then, in an ideal circumstance, they are reduced in the period in which there's no food present in the digestive tract 或 in which there's 非常 little food present in the digestive tract.

安德鲁·休伯曼：

So by eating 大约 the clock, 你're making yourself sicker. By eating at restricted periods of time each 24-小时 天, 你're actually making yourself healthier 和 你 are activating certain processes 那 可以 positively impact both weight, either maintenance 或 loss of weight ... 我们'll talk 关于 weight gain a little later ... 和 positively impacting things like liver health, also the expression of 不同的 things related to 棕色脂肪, the fat 那 增加 你的 代谢 ... 我们 会 return to 这 also a little bit later ... 和 血液 glucose regulation.

安德鲁·休伯曼：

So the takeaway 从 这 研究 ... in fact there are many takeaways 从 这 研究. It's so wonderful ... is 那 liver health, bile acid 代谢, 能量 expenditure, 炎症, liver metabolites, many, many aspects of 我们的 health are impacted by when 我们 eat not just what 我们 eat.

安德鲁·休伯曼：

As 我们 move forward 和 我们 talk 关于 intermittent fasting 对于 eight-小时 windows, six-小时 windows, 12-小时 windows, 对于 all sorts of 不同的 intents 和 purposes, I want to start to establish a foundational 方案 那 all of us, any of us, 可以 use in order to maximize 你的 particular goals. There are some absolutes within 这 realm of time-restricted feeding. Here are a couple of absolutes 那 你 会 want to consider.

安德鲁·休伯曼：

首先 of all, it pays off, in the metabolic sense 和 in the health sense 和 in the weight maintenance 或 loss sense, to not ingest any food in the 首先 小时 之后 waking 和 potentially 对于 longer. So I want to repeat 那. 一 of the key pillars of intermittent fasting is 那, 对于 the 首先 小时 之后 你 wake up 和 potentially 对于 longer, to not ingest any food.

安德鲁·休伯曼：

The 秒 major pillar, 那's well supported by 研究, is 那 对于 the 二 和 ideally 三 小时 prior to bedtime 你 also don't ingest any food, 或 liquid calories 对于 那 matter. 和 我们 会 talk 关于 what it means to break a fast 和 whether 或 not certain liquids, even coffee 和 tea, 可以 break a fast, etcetera, in a few moments. 但 just as a foundation, it's 非常 clear, 从 the 研究 in humans, 那 not eating any food 或 ingesting any calories, liquid 或 otherwise, 对于 the 首先 60 分钟 之后 waking up each 天 和 对于 the 二 to 三 小时 prior to 你的 bedtime, 那's ideal 对于 the parameters 那 我们've discussed earlier, all the 不同的 things, like weight 和 liver health 和 metabolic health 和 so forth.

安德鲁·休伯曼：

The 二 most common questions 关于 intermittent fasting are: when is the ideal time 对于 the eating window? Is it early in the 天, the middle of the 天, 或 later in the 天? 和 how long 应该 那 eating window be? 应该 it be eight 小时 ... 我们 already heard why the eight-小时 window was 首先 established; it was 因为 of 这些 lab conditions 和 the conditions of the particular relationship of the graduate student involved ... 或 应该 it be seven 小时 或 six 小时 或 12 小时? Turns out 那 there'[re] some general frameworks 那 我们 可以 follow in order to answer 这些 questions.

安德鲁·休伯曼：

As 我们 move 进入 这 portion of the discussion I want to highlight a 非常 重要 reference 那 just came out, literally came out last 周, in the journal Endocrine Reviews. 和 the title of 这 review is "Time-restricted eating 对于 the prevention 和 management of metabolic diseases," 尽管 the 数据 in 这 paper go well beyond metabolic diseases. 这 is a paper 从 Satchin Panda's lab. It's a 非常 lengthy review, 与 an enormous table 那's beautifully organized 那 scripts out all the 研究 done in humans, well over 100 研究, looking at time-restricted feeding in athletes, men, women, children, diabetes, no diabetes, etcetera, 与 detailed references 和 description of the outcomes.

安德鲁·休伯曼：

I've spent a lot of time 与 这 review, even though it just came out recently, 和 it is an absolute goldmine resource. It is also the major resource 对于 everything I'm 关于 to tell 你, if 你 会 like to delve deeper 进入 the material.

安德鲁·休伯曼：

So let's deal 与 这 首先 question of: when is the ideal feeding window? 和 here again, 我们're thinking 关于 a schedule of eating 那 involves eating at least once every 24 小时, not 二-天 或 三-天 或 every-other-天 fasts.

安德鲁·休伯曼：

So it turns out 那 the answer to the question: When is it best to eat? is actually best answered by thinking 关于 the other side of the coin, which is: When is it best to fast? So 因为 我们 are fasting 期间 sleep, it's 非常 clear 那 it's best to extend the sleep-related fast either 进入 the 早晨 或 to start it in the 晚上. Now 这 可能 seem kind of obvious, 但 it's actually not so obvious. 你 could place 那 feeding window early in the 天, middle of the 天, 或 late in the 天.

安德鲁·休伯曼：

Let's think 关于 what happens when 我们 sleep. When 我们 sleep, 我们的 身体 undergoes a number of 不同的 processes in the 大脑和身体 in order to recover the cells 和 组织. Many of 你 have probably heard of autophagy, which is 本质上 a cleaning up, a gobbling up, of dead cells 和 cells 那 are injured 或 sick. 和 这 is a natural process 那 occurs. It occurs mainly 期间 sleep, 尽管 not only 期间 sleep.

安德鲁·休伯曼：

Fasting of any kind does tend to 增强 autophagy. It is not the only way to create autophagic conditions. Autophagic conditions 可以 be created simply by following a sub-caloric diet. 和 there are other things 那 一 可以 do in order to trigger autophagy. 但 fasting does trigger autophagy. So when 我们're asleep, the bad cells are getting gobbled up 和 eaten, 和 the good cells also are undergoing certain repair mechanisms mainly related to, 或 at least governed by, 那些 circadian genes 那 我们 talked 关于 earlier, 那些 clock genes.

安德鲁·休伯曼：

So 你're already fasting when 你're asleep. How deep 你 are 进入 那 fast depends on how long it was since 你的 last meal. So if 你 fast early in the 天 和 你've been asleep 对于 five, six, seven, eight 小时 ... I 会 hope somewhere between six 和 eight 小时 对于 most 人们 is going to be beneficial ... when 你 wake up, I mentioned earlier 那 你 don't want to eat 对于 at least the 首先 60 分钟 之后 waking. 但 were 你 to extend 那 fasting to, say, 9:00 AM, 10:00 AM, 11:00 AM, 或 even 12:00 noon, 或 later, 你 are taking advantage of the deep fast 那 你 were in 期间 sleep 和 certainly toward the end of sleep.

安德鲁·休伯曼：

Now, why do I say deep fast? Well, 因为, when 我们 eat, the clearance of 那 food 从 我们的 gut 和 the processes in 我们的 cells 和 organs 那 are related to digestion 和 the utilization of 那 food takes 关于 five to six 小时. So if 你 eat a meal, 和 那 meal lasts 10 分钟, 20 分钟 或 30 分钟, 或 even an 小时, 和 then 你 stop eating, 你've stopped eating 但 你 are not fasting at 那 point. 你 could say 你're fasting 因为 你're no longer putting food 进入 你的 digestive tract, 但 你 are not in a fasted state, 你 are not under conditions of fasting. Later, I'll talk 关于 things 那 你 可以 do to accelerate the transition 进入 fasting.

安德鲁·休伯曼：

So 一 thing is certain, 那 你 want 你的 eating window to be tacked 或 attached to 你的 sleep-based fasting in a way 那 makes it easier 对于 你 to get 进入 the fasted state 对于 a period of time.

安德鲁·休伯曼：

So 我们 可以 view 那 point 从 the perspective of best, better 和 worst. So if 你 are like most 人们 和 你 sleep at 夜间 和 你're waking up somewhere 大约 6:30 AM, 7:00 AM, 或 maybe even 8:00 AM, let's say 你 were to push 你的 fasting window out such 那 你 started eating at noon 和 then 你 stopped eating at 6:00 PM, well, then 你're not eating 从 6:00 PM until ... let's say 你的 bedtime is 10:00 PM. 但 从 6:00 PM to 10:00 PM 你的 身体 is not yet in a fasted state 因为 你 just ate. 然而, 你're starting to taper 进入 a fasted state 之前 sleep. 和 then all 通过 sleep 和 until the next 早晨 和 late 早晨 你 are actually in a fasted state.

安德鲁·休伯曼：

Now, most 人们 find it 非常 hard to only eat in the middle of the 天. So while 那's best, it's ideal 对于 sake of the fasting-related improvements in health, it is not ideal 和 it's not 非常 applicable to most work 和 family 和 social situations. Most 人们 eat breakfast 与 others 和/或 eat dinner 与 others. Some 人们 eat lunch 与 others. 但 in general it's hard to restrict 你的 feeding window to just the absolute middle of the 天. 但 从 a purely health perspective, in a 非常 objective way, 那 会 be the ideal situation.

安德鲁·休伯曼：

Let's imagine a 不同的 pattern of eating, where the feeding window starts in the 下午, starts 大约 2:00 PM 或 even 3:00 PM. Some 人们 don't have much trouble 或 they 可以 train themselves to get their feeding window out to 2:00 PM 或 3:00 PM, 和 then they 会 eat until 10:00 PM 或 11:00 PM.

安德鲁·休伯曼：

If 你 do the math, 你 realize 那 那 feeding window is still pretty short. It still constitutes what 我们 会 call intermittent fasting 或 time-restricted feeding. 但 assuming 那 they go to bed 大约 11:00 PM 或 midnight, they are not actually fasted in sleep, 因为 对于 the 首先 six 小时 或 so of sleep ... maybe five, 但 probably 更多 like six 小时 of sleep ... they're still digesting the food 那 they consumed late in the 夜间.

安德鲁·休伯曼：

It does appear beneficial to grab ahold of 那 sleep-related fast, meaning 你 don't want 你的 feeding window to be too close to bedtime. 和 那's why 我们 came up 与 这 foundational pillar 那 I discussed 与 Satchin earlier, which is at least no eating 对于 the 首先 小时 之后 waking, 但 also no eating within 二 to 三 小时 prior to bed.

安德鲁·休伯曼：

和 因为 我们 all need to sleep 和 sleep is exceedingly 重要 对于 我们的 health of all kinds, 你 want to prioritize sleep. 但 因为 我们 also have to eat, then 你 start to think 关于 这. 和 maybe it's not so good to push 那 feeding window too late in the 天, 因为 when 你 go to sleep, 你're not actually capitalizing on the sleep-related fasting.

安德鲁·休伯曼：

Now, it's not just the case 那 it's easiest to fast while in sleep ... 尽管 那's true, 因为 when 我们're asleep, 通常, 我们're not hungry 或 looking 对于 food 或 foraging 对于 food 或 wanting food 或 trying to resist food. 我们're just sleeping; there is something special 关于 the fasting 那 occurs 期间 sleep 因为 it's associated 与 a number of processes 那 relate to the so-called glymphatic 系统; the movement of lymph-like fluids 和 other fluids 通过 the 大脑, a kind of sweeping out garbage disposal, if 你 会, a clearing out of the metabolic debris 和 some of the autophagy 那's associated 与 bad processes in the 大脑.

安德鲁·休伯曼：

So 我们 could do a whole episode on 这, 但 本质上, 期间 sleep, 和 in particular 期间 fasted states of sleep, 我们 are undergoing a number of automatic cellular processes 那 clear out debris 从 我们的 大脑, 增强 cognition 或 at least offset dementia ... 这 is now well established ... as well as a number of the same processes occurring in the organs of 我们的 身体.

安德鲁·休伯曼：

So what 我们're starting to see here is 那 there are a number of constraints on when 你 可以 eat. Now, I 会 be remiss if I didn't acknowledge the social constraints 和 the real life constraints. Some of us, 因为 我们 want to eat 与 我们的 family 和 因为 我们的 family 或 我们的 significant others eat 大约 8:00 PM 或 9:00 PM 和 那's the only time 我们're together, 你 have to eat late in the 天. 和 那's certainly not a sin. I'm not saying 那's good 或 bad. Here, 我们're trying to establish, if 你 recall, best, better 和 worse.

安德鲁·休伯曼：

So 从 both a practical 和 a health perspective, 和 a purely objective view of how intermittent fasting works 和 可以 benefit us, starting to eat each 天 somewhere 大约 10:00 AM 或 大约 noon, 和 then allowing a feeding window 那 goes until 6:00 PM 或 maybe 8:00 PM, 那 seems, to me, at least based on the 数据 和 what I understand 关于 typical cultures where 人们 eat in the daytime 和 in the 晚上, 那 seems to me like the kind of schedule 那 会 allow 你 to get the most out of intermittent fasting, time-restricted feeding, 但 does not set 你 up to be 确实 out of sync 与 the social rhythms in most cultures.

安德鲁·休伯曼：

If 你 think 关于 it 从 the perspective of, say, a noon-to-eight feeding window, what 你'll find is 那 你're able to eat lunch 与 others, if 你 like, 或 by yourself; 你 会 be able to eat dinner at a reasonable 小时. At least in most countries, in most cultures, eating dinner somewhere between 6:30 PM 和 7:00 PM is typical.

安德鲁·休伯曼：

When 你 say a feeding window 那 goes until 8:00, 那 doesn't mean sitting down to dinner at 8:00, 那 means 你的 last bite of food 或 ingestion of any liquid calories was at 8:00 PM. Assuming 那 你 go to bed somewhere between 10:00 PM 和 1:00 AM, 那 allows 这 tapering off 或 这 transition 从 feeding to a fasted state 和 still allows 你 to capitalize on the special period of fasting 那 is sleep-related fasting. 和 again, I want to emphasize 那 the fasting 那 occurs 期间 sleep is vital 和 eating too close to sleep 会 disrupt 那 fasting-related sleep.

安德鲁·休伯曼：

Now, there are a number of caveats 和 details related to 这. 和 there's an 重要 caveat 和 detail related to 人们 那 are specifically interested in increasing 或 maintaining 肌肉 mass.

安德鲁·休伯曼：

So, 首先, let's talk 关于 food volume 和 food type, 和 how 那 relates to whether 或 not 你 quickly 或 slowly enter a fasted state. 因为 clearly, when 我们 talk 关于 a feeding window, 那 feeding window could include any number of 不同的 foods. It could involve cake 和 ice cream, pizza, hamburgers, plants, fruit, whatever it is, 或 it could involve just fats 或 just proteins, etcetera.

安德鲁·休伯曼：

There are at least 三 factors 那 are going to govern how quickly 你 transition 从 ingesting food to a fasted state. Remember, as 你 ingest 你的 last bite 或 sip of calories, 那's not when the fast begins. 那 可能 be when the fasting begins on 你的 watch 或 on 一 of 这些 apps 那 I'll refer to later which 可以 help 你 track 你的 fasting 和 eating windows, 但 那's not when it actually begins 因为 你的 身体 is still seeing food, 你're actually carrying 大约 food inside of 你. Even though 你're not putting it 进入 你的 mouth, 你 are still eating in some sense.

安德鲁·休伯曼：

So it 应该 be somewhat obvious 那 非常 large meals are going to take longer to digest than 非常 small meals. So 那 会 impact how slowly 或 quickly 你 migrate 从 a fed state to a fasted state. There's no way I 可以 spell out what exact volume of food 你 应该 ingest based on the size of 你的 stomach, etcetera. 但 你're all familiar 与 being extremely full, 非常 full, comfortably full, somewhat full, 或 not feeling full 和 feeling hungry. So learning to gauge food volume is 重要.

安德鲁·休伯曼：

Also, foods 那 include some fats 或 a lot of fats 会 tend to slow gastric emptying time. 和 depending on the kind of fats, it could mean 那 a given meal is digested within 三 小时 versus five 小时. So 更多 fats 可能 be ... a large meal 与 a lot of fats is going to take five 或 six 小时. A smaller meal 与 更少 fat is going to be digested 更多 quickly. Consuming calories in liquid form is going to mean 那 gastric emptying time is going to be faster.

安德鲁·休伯曼：

和 then of course there's the glucose 和 the insulin aspect to it, which is 那 foods 那 lead to big steep rises in glucose, like pure sugars, then 你的 glucose 会 drop. 然而, if they're combined 与 fats, then it tends to be a 更多 gradual rise in glucose 和 it's 更多 sustained, etcetera. Fibrous foods 会 also create a 更多 long-lasting sustained 释放 in glucose.

安德鲁·休伯曼：

The 重要 thing here is to establish a feeding window 那 你 可以 comfortably manage, meaning 那, on average, 你 可以 obey a six-小时 feeding window 或 an eight-小时 feeding window 或 a 10-小时 feeding window. 和 then to place 那 feeding window in a social 和 life context 那 你 可以 manage on a regular basis.

安德鲁·休伯曼：

Now, there are 二 key points 那 have been gleaned 从 the scientific 数据 关于 这 feeding window 和 when to place it. 和 这 is based on a 确实 重要 experiment 那 Satchin 和 his colleagues have been doing. There's a website 那 they have, a zero-cost website called MyCircadianClock. 你 可以 go to 这 website free of cost. There are a number of 重要 resources there.

安德鲁·休伯曼：

但 what they've done is they've examined the feeding behavior of thousands of 人们. 人们 会 take a picture of the food they're 关于 to eat 和 it enters 进入 their account ... maybe 你的 account, if 你 create 一 ... on MyCircadianClock. 和 they do 这 over many 天 或 周.

安德鲁·休伯曼：

What's great 关于 这 is it establishes what's 本质上 called a feedogram; a time in which 人们 ate. 和 a number of 重要 findings have emerged 从 这些 feedograms across large populations of 人们 in 不同的 time zones, 与 不同的 schedules, etcetera.

安德鲁·休伯曼：

首先 of all, almost everybody underestimates their feeding window. Meaning 人们 who think 那 they are on an eight-小时 feeding window 或 a six-小时 feeding window, when their 数据 are analyzed it almost is 总是 the case 那 they're actually on a feeding window 那's 一 或 even 二 小时 longer than they think.

安德鲁·休伯曼：

你 think, "Well, how could 那 possibly be? If 人们 are taking their 首先 bite at noon 和 they're taking their last bite at 8:00 PM, well 那 must mean 那 they are on 那 feeding window of eight 小时?" 和 it turns out 那 人们 cheat. 但 they don't cheat in any kind of obvious way, they 可能 have a glass of wine 之后 dinner 或 they'll have a cup of tea 和 a little bite of a cookie. So when 人们 are honest ... 和 they are honest in most cases, 对于 这 experiment ... what 你 find is 那 most 人们's eating window is actually quite a bit longer.

安德鲁·休伯曼：

So in discussing 这 与 Satchin 和 reviewing the literature, it's clear 那 if 你'd like to be on a 10-小时 feeding window, 那 你 应该 probably select an eight-小时 feeding window, 因为 there's 总是 a little bit of a taper on either side of 那 eating window. 非常 few 人们 are extremely strict 关于 这些 eating windows. It's just hard to do in the context of life events 和 social gatherings 和 family 和 so forth.

安德鲁·休伯曼：

So as 我们 build forward 你的 ideal fasting/time-restricted feeding schedule, 我们 now have several 不同的 rules 那 我们 可以 list out. 首先, at least no food 对于 the 首先 小时 之后 waking up. At least 一 小时. 二, no food intake 对于 二, 和 ideally 三 小时, prior to 你的 bedtime.

安德鲁·休伯曼：

三, if 你 want to select an eight-小时 feeding window, then 你 应该 probably 专注 on a six- 或 seven-小时 feeding window 因为, in reality, 你的 feeding window is going to be longer. Reality, meaning real life constraints. 和 if 你'd like to be on a 10-小时 feeding window, 你 应该 probably select an eight- 或 a nine-小时 feeding window, 因为 the way it plays out is 那 人们 almost 总是 eat outside of their eating window somewhat.

安德鲁·休伯曼：

The other nice thing 关于 selecting a slightly shorter eating window than is comfortable 对于 你 is 那 it takes 进入 account 那, as 你 take 你的 last bite 或 你的 last sip of calories, there's 这 time 或 taper 之前 which 你 are actually in a fasted state. 和 因为 你're eating 不同的 things on 不同的 天 presumably, some foods leave 你的 gut 更多 quickly, some things spike 你的 insulin 和 你的 glucose 更多 than others, sometimes 你 eat 更多 fat, sometimes 更少 fat. 这 allows 你 to fall well within the margins of the benefits of time-restricted feeding 那 have been demonstrated in humans, which generally involve an eight-小时 window 或 so.

安德鲁·休伯曼：

So I think 这 eight-小时 window 或 six-小时 window is a good thing to shoot 对于, 对于 most 人们. Some 人们 ... 和 我们 会 discuss the exceptions ... 但 some 人们 truly are exceptions to 这. They just require 更多 food. 和 along 那些 lines, I just now briefly want to touch on some of the 研究 那 have looked at using a 非常 short feeding window of 关于 four 小时.

安德鲁·休伯曼：

Nowadays, a number of 人们 are doing the so-called 一 meal per 天 或 are restricting their feeding window to just four 小时 或 six 小时. 和 那 turns out to be an interesting strategy. The 数据 大约 it actually are a little bit surprising.

安德鲁·休伯曼：

一 surprising thing to leap out of 这 massive literature review on time-restricted feeding in humans is 那 relatively short feeding windows of, say, four to six 小时, do produce a number of positive health effects, things like 增加了 insulin sensitivity which 我们 know is good ... remember, type 2 diabetes is a reduction in insulin sensitivity ... improvements in beta cell function in the pancreas, 降低了 血液 pressure, 降低了 oxidative 压力, 降低 in things like 晚上 appetite. So positive health effects 和 psychological effects in general.

安德鲁·休伯曼：

然而, they either produce no change in 身体 weight 或 they tend to produce even 增加 in 身体 weight. Now, of course there's variation between 个体 和 between 研究, 但 这 is somewhat surprising. So the eight-小时 feeding window seems to be 非常 beneficial across almost all the parameters 那 我们've discussed: 炎症, weight loss, fat loss, etcetera. 和 adherence, I 应该 mention, 人们's ability to stick to the diet, seems quite good on 这 eight-小时 feeding windows. 但 when 人们 try 和 undergo 非常 short feeding windows of four to six 小时 it seems 那 they are overeating in 那 four to six 小时, at least overeating 与 respect to their metabolic needs.

安德鲁·休伯曼：

Now, the contrast to 这 is the so-called 一 meal per 天 schedule. 非常 few 研究 on 一 meal per 天. 一 meal per 天, unless it's a 非常, 非常 long meal, a sort of feast, 通常 会 not last four to six 小时. I guess it sort of depends on how 你 define a meal. 但 when 你 look at the 非常 few ... I 应该 emphasize again, 非常 few 研究 on 一 meal per 天, 人们 通常 maintain 或 lose weight on the 一 meal per 天 schedule.

安德鲁·休伯曼：

So what 我们 可以 say is 那 the seven- to nine-小时 feeding window produces all of the major health benefits of time-restricted feeding, as well as being pretty straightforward 对于 most 人们 to adhere to on a regular basis ... 和 on a regular basis, turns out to be 非常 重要. I'll get back to 那 point in a moment ... whereas the four- to six-小时 eating window doesn't seem to serve 人们 as well as, say, a seven- 或 eight-小时 eating window, simply 因为 人们 are overeating 期间 那 eating window. 和 the 一 meal per 天, while perhaps ideal 对于 certain 人们's schedules, may actually cause 人们 to undereat. 和 in some cases 那 可能 be what 人们 want, they actually want to undereat.

安德鲁·休伯曼：

但 when 我们 start thinking 关于 表现 in work 和 in sport, 和 when 我们 start considering 激素 health 和 激素 production, fertility, 那's when 我们 可以 确实 start to look at the seven- to nine-小时 feeding window, versus the four- to six-小时 feeding window, versus the 一 meal per 天 type feeding window 与 some 不同的 objectivity. 我们 可以 start to look at it 通过 a 不同的 lens. 因为 it turns out 那 when 你 place the feeding window, 和 how long 那 feeding window is, actually 会 impact a number of other things, in particular 激素, 那 可以 be 非常 重要 对于 a number of things related to sex 和 reproduction, it 可以 be related to 表现 at work, 表现 in athleticism. 和 there are excellent 研究 on 这, so let's explore 那些 now.

安德鲁·休伯曼：

So let's talk 关于 some conditions where having the feeding window early in the 天 会 actually be 非常 beneficial. There was a 研究 那 was published recently in Cell Reports, again, Cell Press journal, excellent journal, peer-reviewed, 非常 stringent, 从 Aoyama et al. So 这 is A-O-Y-A-M-A et al. 这 was published just recently, July 2021, 那 looked at the distribution of protein intake in 不同的 meals delivered either early in the 天 或 later in the 天. 和 I'm summarizing here quite a lot, 但 I 应该 mention 那 这 研究 was performed in both mice 和 humans, same paper, mice 和 humans, 和 involved hypertrophy 训练, 本质上 increasing the weight bearing of given limbs to try 和 induce hypertrophy, which is the growth of 肌肉 组织. It does appear 那 肌肉 组织 is better able to undergo hypertrophy by virtue of the fact 那 there's better 或 enhanced protein synthesis early in the 天 因为 of the expression of 一 of 这些 particular clock genes called BMAL, B-M-A-L.

安德鲁·休伯曼：

BMAL regulates a number of 不同的 protein synthesis 通路 within 肌肉 cells, such 那 eating protein early in the 天 supports 肌肉 组织 maintenance 和/或 growth. 和 in 这 研究, they also looked at the effects of supplementing so-called BCAAs, branched-chain amino acids, which is popular in bodybuilding circles 和 in 力量 训练 circles. BCAAs are essential components of a number of 不同的 foods 但 可以 also be supplemented. The takeaway of 这 研究 is pretty straightforward 然而. The takeaway is if 你的 main interest is maintaining 和/或 building 肌肉, then it 可以 be beneficial to ingest protein early in the 天. 你 会 still want to obey 这, what 我们're calling a kind of foundational, rule of not eating any food 对于 the 首先 小时 post waking 或 at least the 首先 小时 post waking.

安德鲁·休伯曼：

和 the cutoff 对于 when 你 会 want to eat protein 会 be sometime 之前 10:00 AM, 和 there I'm averaging across a number of 不同的 situations. 但 in general, 这 BMAL expression is such 那, let's say 你 wake up at 7:00 AM; 你的 main interest is in hypertrophy 或 maintenance of 肌肉, then 你 会 want to ingest some protein sometime 之前 10:00 AM. 但 obviously, if 你're interested in getting the health effects of intermittent fasting, 那 你 wouldn't ingest any food 对于 at least the 首先 60 分钟 upon waking.

安德鲁·休伯曼：

Now, it's not as if at 10:01 AM a gate slams shut 和 你 可以't generate hypertrophy. Of course, 那's not the case. 然而, it's 非常 interesting 那 it doesn't matter when the resistance 训练, the load-bearing 运动, occurs in the 24-小时 cycle. So whether 或 not, in other words, 人们 are 训练 early in the 天 或 they're 训练 late in the 天, it still appears 那 ingesting protein early in the 天 favors hypertrophy, 或 那 一 is better, 或 I 应该 say 更多 easily able to access hypertrophy by way of 这些 clock-regulated protein synthesis mechanisms by ingesting protein early in the 天. In no way, shape, 或 form does 这 研究 say 那 ingesting protein later in the 天 is somehow bad 对于 你. It just emphasizes the positive effects of ingesting protein early in the 天 对于 sake of 肌肉 maintenance 和/或 hypertrophy. So if 你're somebody who's mainly concerned 与 肌肉 maintenance 和 hypertrophy, then it may make sense to move 那 feeding window earlier in the 天.

安德鲁·休伯曼：

和 certainly, there are 人们 out there who are interested in 肌肉 maintenance 和 hypertrophy who aren't doing intermittent fasting at all, 和 那's also perfectly fine. 但 这 just so happens to be an episode 关于 intermittent fasting 和 time-restricted feeding. There are, of course, modes of eating where 一 eats small meals spread throughout the 天 或 weighs meals differently such 那 meals early in the 天 are larger than later in the 天 或 vice versa. There are near infinite number of ways to organize 这, 但 if 你 are somebody who's interested in deriving the many clearly established health effects of time-restricted feeding, 和 你 are somebody who 会 like to maintain 或 build 肌肉, then ingesting proteins in the early part of the 天 会 be 重要 to 你 at least on the basis of 这些 结果.

安德鲁·休伯曼：

因此, 那 eight-小时 window, 那 我们've established as 更多 或 更少 ideal, shifted to the later part of the 天 可能 not be as beneficial 对于 你. Now, I 可以 just personally say 那 对于 me, when I wake up in the 早晨, it's 非常 easy 对于 me to not eat until noon 或 1:00 或 2:00 PM. Eating early in the 天 is actually somewhat of a challenge. I discussed 这 point 与 Satchin 因为 我们 were talking 关于 how is it 那 一 可以 move their feeding window 或 place themselves onto a 不同的 schedule of intermittent fasting. It's 非常 clear 那 一 needs to provide a transition period in order 对于 那 to happen. 你 应该 allow yourself a transition period of anywhere 从 一 周 to 10 天 in which 你 shift 你的 feeding window by 关于 an 小时 each 天 或 so. 和 then, once 你 establish a feeding window 那 feels comfortable 对于 你 和 那 你 think 你 可以 maintain over time, 那 你 simply maintain 那 feeding schedule 对于 at least 30 天, 但 ideally, 你 会 do 那 indefinitely.

安德鲁·休伯曼：

Now, 这 turns out to be 重要 based on 数据 那 they've gleaned 从 这 My Circadian Clock massive experiment 那 they've been doing where 人们 are entering the times 那 they're feeding 和 eating. Excuse me. Anytime 我们 talk 关于 mice, I 总是 think 关于 feeding 因为 I come 从 a background 和 my lab works on both laboratory mice 和 on humans. Anytime I think 关于 humans, I think 关于 eating, 但 of course, they're the same thing.

安德鲁·休伯曼：

The interesting thing to emerge 从 那 非常 large 数据 set in humans is 那 when 人们 log their feeding times, as I mentioned 之前, oftentimes they think they're eating in an eight-小时 window, 但 they are actually eating in a much broader window. 然而, even 对于 人们 那 are 非常 good 关于 restricting their feeding to a four- 或 six- 或 eight-小时 window, if they're 非常 strict 关于 the start 和 stop times of when they ingest calories, 一 of the findings 那's 确实 been 重要 to note is 那 almost every individual has a lot of drift in when 那 eating window resides in their 24-小时 period. In particular, on the weekends, 人们 are either extending 或 shifting their feeding window in a way 那 makes it seem 那 they've traveled to another time zone 和 are eating according to another time zone, 和 这 is extremely 重要.

安德鲁·休伯曼：

As I mentioned earlier, based on the 2012 研究 从 Satchin's lab where eating at a particular phase of each 24-小时 cycle 可以 help 增强 the expression of 这些 clock genes, if 你 are eating within a 非常 strict 或 semi-strict feeding window, 但 那 feeding window is migrating 大约 从 天 to 天 或 five 天 a 周, 你're 确实 organized 关于 when 那 falls. Let's say, 对于 sake of example, 从 noon to 8:00 PM, noon to 8:00 PM Monday, noon to 8:00 PM Tuesday, Wednesday noon to 8:00 PM, Thursday 和 so forth. 但 then on a Saturday, it's becoming 11:00 AM 和 你're ending it early 或 perhaps 你 are starting early in the 天 on Sunday. 你're having brunch 那 starts at 9:30 或 10:00 和 then it's extending out still just eight 小时, 但 it's shifting 大约, 那 可以 cause disruptions in 这些 circadian clock mechanisms 那 cause disruptions in the downstream effects of eating 那 are taking at least 二 to 三 天 to recover 从.

安德鲁·休伯曼：

So obviously, 我们 don't want to be overly neurotic 关于 这 stuff, 但 因为 这 is an episode 关于 the science of intermittent fasting 和 time-restricted feeding, as 重要 as how long 你的 feeding window is, is where 那 feeding window resides in each 24-小时 cycle, 和 perhaps even 更多 重要 than 那 is 那 it be fairly regular where 那 feeding window resides 因为 even if 你 have a 非常 short feeding window, if it's drifting 大约 从 天 to 天, 那 actually offsets a number of the positive health effects of intermittent fasting.

安德鲁·休伯曼：

So to 确实 just underscore the way 那 这些 不同的 pieces of the biological puzzle fit together, if 你 are 非常 strict 或 semi-strict 关于 你的 eight-小时 feeding window, 但 on the weekends, 那 eight-小时 feeding window is falling later than it normally 会 期间 the middle of the 周, it is as if 你 are going to bed later, even if 你're going to bed at the same time, at least 从 the perspective of metabolic health, 因为 of the way 那 eating impacts 这些 clock genes 和 impacts, 或 I 应该 say subtracts the sleep-related fasting 那 你 会 normally experience if 你 were to finish eating a couple 小时 之前 bedtime.

安德鲁·休伯曼：

So again, 我们 don't want to create any overly obsessive 或 neurotic 专注 on 这. I think 那 most all 人们 could benefit 从 a time-restricted feeding schedule, 但 they 应该 确实 think hard 关于 what they 可以 stick to on a regular basis 和 understand 那 they tend to underestimate the feeding window 那 they actually are partaking in 和 那 they 应该 place 那 feeding window in a portion of the 24-小时 cycle 那 they 可以 be consistent on most 天.

安德鲁·休伯曼：

和 I want to emphasize most, again, 因为 我们 are not laboratory mice. 我们 don't have a graduate student coming in 对于 eight 小时 a 天 因为 那's what their significant other 会 allow them to do 和 then removing the food 从 我们的 jowls 和 从 我们的 cages. 我们 have access to food pretty much 24 小时 a 天. Along 那些 lines, 然而, there are things 那 我们 可以 all do 那 会 allow us to offset some of the drift, if 你 会, 那 我们 experience 或 那 我们 induce in terms of when 我们的 feeding window occurs 或 那 the feeding window 可能 push out a little later 和 then 因此 start a little later the next 天. There are things 那 我们 可以 do 和 there are things 那 我们 可以 take. 和 so I'd like to discuss 那些 briefly.

安德鲁·休伯曼：

So throughout 这 episode, I've 更多 或 更少 been alluding to the fact 那 when 你 eat, there's some period of time afterwards in which 你're actually still eating, at least 从 the perspective of 代谢 因为 glucose is up, insulin is up, 和 你're undergoing 不同的 metabolic 和 digestive processes 那 don't 确实 speak to 你 being in a fasted state, right? It's not just 关于 when 你 take 你的 last bite 或 你的 last sip. 然而, there are things 那 我们 可以 do to accelerate the transition 从 a fed state to a fasted state, 和 so I'd like to discuss what 那些 are.

安德鲁·休伯曼：

和 I want to emphasize 那 the term "fed state" is probably a better way to think 关于 it than eating 或 not eating 因为 我们 think of eating as the verb. 我们're eating. 我们're eating. Okay, 我们're done eating. I'm fasting now, 但 你're not actually fasting 因为 你 are fed. So 我们 应该 确实 think 关于 fed 和 unfed states 因为 从 a cellular process's perspective 和 从 a health perspective, 那's actually what 你的 身体 和 你的 系统 are paying 注意力 to. 和 by now, 与 everything 那 我们've laid out, I think 那 应该 be intuitive to understand.

安德鲁·休伯曼：

So there's a fun 和 exciting concept related to 这, which is glucose clearing. 你 may have heard the old adage 那 if 你 take a 20- 或 30-分钟 walk 之后 dinner, 那 it accelerates the rate at which 你 digest 那 food. 和 indeed it does. Clearing out of glucose 从 你的 系统 可以 be accomplished 通过 a number of 不同的 means, 但 light movement 或 运动 does 增加 gastric emptying time. So 对于 instance, if 你 were to eat a meal 那 ended at 8:00 PM 和 then plop to the couch, watch TV, 或 get on 你的 computer, 或 go to sleep, it 会 be five 或 six 小时 until 你 have transitioned 从 a fed state to a fasted state. 然而, 你 可以 accelerate 那 considerably by taking a 20- 或 30-分钟 just light walk. It doesn't have to be speed walking. It certainly doesn't have to be jogging, 但 just walking outside 或 moving 大约. So glucose clearing is an 重要 aspect of the transition 从 the fed state to the fasted state, 和 just a light walk 可以 allow 你 to do 那.

安德鲁·休伯曼：

Now, if 你 可以't get outside, some 人们 会 go 通过 the gymnastics literally of doing things like 空气 squats 和 push-ups 和 things like 那. 和 indeed, 那些 会 增加 the expression of things like GLUT4 和 things 那 mobilize glucose 进入 肌肉 和 things of 那 sort. 但 under most conditions, most 人们 aren't doing push-ups 之后 dinner. 或 certainly if 你've had a big meal, just taking a light walk 可以 be beneficial. In addition, 你 could consider doing intense 运动. Now, 你 wouldn't necessarily want to do 那 immediately 之后 eating. So let's take a look at what high-intensity 训练 of any kind does to 血液 glucose 因为 in 这 case, it turns out 那 when 你 do high-intensity 训练, [it] actually has opposite effects on 血液 glucose depending on whether 或 not 你 do it early 或 later in the 天.

安德鲁·休伯曼：

So a fairly recent 研究 looked at so-called HIIT 训练, high-intensity interval 训练, which of course 可以 take many 不同的 forms. It 可以 take the form of 回路 训练 与 weights. It 可以 take the form of burpees 和 push-ups 和 sprints 和 all sorts of 不同的 things. 但 high-intensity interval 训练 is 通常 训练 那 gets 人们's 心脏 rates up, well above 70% of maximum, 和 then brief periods of rest, 和 then repeating. 和 how long the high-intensity interval 训练, of course, 会 also vary. There are 非常 brief six- 或 12- 或 15-分钟 workouts. Some 人们 可以 carry on 与 high-intensity interval 训练 对于 up to 45 或 maybe even 60 分钟 in extreme cases. 但 when 你 look at the 研究 那 have explored high-intensity interval 训练 和 its effect on 血液 glucose, there are a couple of 研究 那 leap out. 对于 instance, 一 那 emphasized 那 血液 glucose 水平 会 actually 增加 if high-intensity interval 训练 is performed early in the 天 和 会 降低 if high-intensity interval 训练 is performed later in the 天.

安德鲁·休伯曼：

Now, the purpose 对于 这 exploration was not to explore clearance of 血液 glucose 对于 sake of intermittent fasting. It was mainly focused on athletic 表现 和 whether 或 not 那 was better early in the 天 或 later in the 天, etcetera. 但 我们 可以 extract some information 从 这些 研究 那 are beneficial 对于 sake of understanding glucose clearing. If 你 have ingested food throughout the 下午 和 晚上 和 late in the 天 和 你're thinking 关于 going to sleep 和 你'd like to enter sleep in a way 那 is 更少 fed 和 更多 fasted, then engaging in high-intensity interval 训练 in the 下午 会 lower, 或 晚上, I 应该 say, 会 lower 血液 glucose. 和 in 那 way, 会 help 你 accelerate 你的 transition 进入 the fasted state, provided 你 don't ingest something 之后 the high-intensity interval 训练.

安德鲁·休伯曼：

Now, is the 增加 in 血液 glucose 那 occurs 从 high-intensity interval 训练 early in the 天, is 那 detrimental? Not necessarily so. 那 oftentimes is associated 与 the shuttling of nutrients to the 肌肉 那 have just done a lot of hard work. So it's not 那 high-intensity interval 训练 应该 not be done early in the 天. In fact, 对于 many 人们, including myself, 训练 early in the 天, just 对于 the way 那 my psychology 和 biology works, is 总是 better 对于 me than 训练 later in the 天. 和 the other 重要 thing to mention is 那 high-intensity interval 训练 done late in the 天 可以 be beneficial 从 the perspective of glucose clearing, lowering 血液 glucose, 和 helping transition 从 the fed to the fasted state in preparation 对于 sleep.

安德鲁·休伯曼：

然而, if 你're ingesting caffeine 或 anything to engage in 那 high-intensity interval 训练 in a way 那 prevents 你 从 getting to sleep, well then it's going to be detrimental overall. So the reason I mention 这 is, of course, 因为 it's nice to know 那 light walks 之后 dinner 或 any other meal 对于 那 matter 或 high-intensity interval 训练, provided it's done in the 秒 half of the 天, 可以 lower 血液 glucose 和 speed the transition 从 fed to fasted states. 但 I also mention it 因为 what 我们 are 确实 trying to achieve when 我们 partake in intermittent fasting, so-called time-restricted feeding, is what 我们're 确实 trying to do is access unfed states 或 fasted states. It's not 确实 关于 when 你 eat 和 what 你 do. It's 关于 extending the duration of the fasting period as long as 你 可以 in a way 那's still compatible 与 你的 eating, right? Not the other way 大约.

安德鲁·休伯曼：

和 这 gets back to 这 key feature of 我们的 biology, which is 那 what 我们 eat, when 我们 eat, when 我们 运动, when 我们 view light, it's 关于 setting a context 或 a set of conditions in 你的 大脑和身体. So it's not so much 关于 the activities 那 你 undergo, it's 关于 the activities 你 undergo 和 their relationship to 一 another over time. 和 so in 这 way, it 确实 beautifully highlights the way 那 你的 biology is interacting all the time.

安德鲁·休伯曼：

Light is setting when 你're going to be awake 和 when 你're going to be asleep. When 你 eat is going to be determining when 你're going to be awake 和 when 你're going to be asleep. 和 when 你 eat is also going to be determining when 你 are able to clear out debris 从 你的 大脑和身体 和 repair the various cells 和 mechanisms of 你的 身体 when 你're able to 减少 那些 炎症性的 cytokines throughout 你的 身体. 和 这 is 确实 the beauty of time-restricted feeding, which is it's not 确实 关于 restricting 你的 feeding, it's 关于 accessing the beauty of the fasted state.

安德鲁·休伯曼：

Now, there are other ways to clear out 血液 glucose 那 involve supplements 或 prescription drugs. 这些 are so called glucose disposal agents. Glucose disposal agents, such as metformin, which is a prescription drug, 或 berberine, which is an over-the-counter substance, 会 lead to 非常 dramatic reductions in 血液 glucose. 和 so they shift 你 从 a fed to a fasted state. 和 I know many 人们 who take berberine 之前 eating meals 那 include a large number of carbohydrates, 对于 instance, as a way to clear out glucose. Now, I've tried berberine 之前 和 what I 可以 tell 你 is 那 if 你 take berberine, which by the way is 非常 much like metformin, its effects are almost identical to metformin, in fact, 但 it's much 更少 expensive, 和 it's over-the-counter. If 你 take berberine 和 你 have not ingested carbohydrates, many 人们, including myself, experience a splitting headache. 你 become hypoglycemic 因为 it is a glucose clearing agent.

安德鲁·休伯曼：

So if 你're going to experiment 与 things like metformin 和/或 berberine 或 相似的, 你 want to be 非常 cautious 那 你're not clearing out 血液 glucose 那's already low. 和 the dose response 对于 这 varies tremendously 从 一 individual to the next, 和 there's a strong circadian component. So some 人们 react 非常 well to berberine early in the 天, 但 find 那 later in the 天 it provides extreme headaches. 对于 some 人们, it's the opposite. So I caution 你 in exploring things like berberine 和 metformin 那 你 应该 expect to experience a number of physical 和 psychological effects 那 may work 对于 你, 可能 be great 对于 你, 但 可能 also not be great 对于 你.

安德鲁·休伯曼：

Nowadays, there are a number of commercially available continuous glucose monitors. I've tried 一 of 这些. It involves putting what's 本质上 a patch 与 a little needle 那 goes 进入 你的 皮肤, which is continuing, continually, excuse me, monitoring 你的 血液 glucose, 和 你 可以 look at it at an app on 你的 phone. 和 你 可以 learn a lot 那 way 关于 how 不同的 foods impact the 增加 和 降低 in 血液 glucose. If 你're doing experiments 与 berberine 或 metformin, 你 可以 see how 那些 impact 你的 血液 glucose. 你 可以 see how 运动, HIIT 训练, 或 otherwise, impacts 血液 glucose. Excuse me again.

安德鲁·休伯曼：

It's 非常 hard to assess 血液 glucose 没有 a continuous 血液 glucose monitor, 和 if 你're not using 一, 你're mainly going to be relying on subjective things like, "Oh, I feel like I have low 血液 sugar, 或 I feel shaky like I have high 血液 sugar" 或 shaky 因为 你 have low 血液 sugar. So I have to say 那 glucose clearing agents 那 involve a walk 或 运动, moderate 或 intense, are going to be a lot easier to titrate 和 adjust the 水平 of than things 那 你're going to take where 你 have to ingest the dosage. 和 then once 你 ingest a certain dosage, 你're along 对于 the ride, at least until the effects of 那 particular compound wear off.

安德鲁·休伯曼：

It doesn't mean 那些 things don't have utility. It doesn't mean 人们 aren't using them, 因为 many 人们 are, 但 they are potentially a 非常 sharp blade 那 is a double-sided blade. So I encourage 你 to approach 那些 与 caution if 你 decide to at all. It's worth thinking 关于 what the low 血液 glucose state is 和 why it's beneficial as well as why it 可能 produce headaches, 和 in some cases 可以 also adjust the effects of other 激素. In the fasted state, a number of 不同的 proteins 那 are expressed in cells undergo changes in their expression. 我们 talked 关于 这 earlier. When 我们 are fasted, 我们 tend to 减少 the activity of a particular protein called mTOR, mammalian target of rapamycin. mTOR is 非常 active in cells while they are growing. So throughout development, it's also 非常 active in cancers of various kinds. mTOR needs to be what's called phosphorylated. If 你 don't know what 那 means, don't worry 关于 it. 但 phosphorylation is a manner in which certain proteins are altered so 那 they 可以 actually be functional within cells.

安德鲁·休伯曼：

mTOR is associated 与 cell growth of all kinds, healthy 和 unhealthy. When mTOR is phosphorylated, there's a marker called pS6. So phospho-mTOR expresses pS6. If 这 is all escaping 你, don't worry 关于 it. Phospho-mTOR 和 pS6 are reduced by fasting. Now, 这 makes sense if 你 think 关于 it 因为 eating 和 growth are associated 与 each other. Fasting is not necessarily anti-growth, 但 it is not pro-growth. 和 when 我们 fast, 我们 see 增加 in cells of things like AMPK, the sirtuins, things like transcription factors like FOXO, ATF, 和 ketones 或 ketone bodies. 你 may have heard of the ketogenic diet.

安德鲁·休伯曼：

What's the point of all 这 biochemistry? It's not to just blitz 你 与 a bunch of cellular biology 和 biochemistry. It's to say 那 我们 have cell growth 通路 involving mTOR 和 pS6 和 我们 have cell repair 和 cell shrinkage processes 那 are associated 与 AMPK, the so-called sirtuins, which Dr. David Sinclair 从 Harvard 和 others are famous 对于 discovering 和 understanding things like AMPK. 这些 二 不同的 divergent 通路 of cell growth 和 cell breakdown 和 repair, 和 by breakdown, I mean actual clearance, autophagy, 和 repair. 那些 可以 be triggered by being in either the fed 或 the fasted state. So 一 way I'd like 你 to think 关于 the fed state, not just eating 但 having recently eaten 或 the fasted state meaning high 血液 glucose 和/或 你've recently eaten 或 are currently eating 或 drinking calories, is 那 when 你 eat 或 when 你 don't eat, when 你're fed, when 你're fasted, 你 are either promoting cellular growth of all kinds 或 你're promoting cellular repair 和 clearance of all kinds.

安德鲁·休伯曼：

和 so again, 这 is 关于 setting conditions in the 大脑和身体. It's not so much 关于 when 你 eat food A 或 B; it leads to 增加 in mTOR. Anytime 你 eat any food, doesn't matter if it's plant based, animal based, fat, protein, carbohydrate, doesn't matter, 你 are biasing 你的 系统 towards a biochemical state of cell growth. Anytime 你 haven't eaten 对于 a while 或 血液 glucose is low, 你 are biasing 你的 系统 toward a state of cellular repair. 和 这 is why 人们 who do not suffer 从 any 血液 glucose regulation issues take things like berberine as glucose disposal agents 或 take metformin. I'm not necessarily suggesting 那 你 do 那, 但 it's 因为 那些 things mimic fasting. They create situations in the 身体 那 promote things like AMPK 和 the sirtuins 和 others to push 你的 身体 和 你的 系统 down a route of repair even though 你 可能 have just eaten a meal an 小时 ago.

安德鲁·休伯曼：

Along the lines of the health benefits of intermittent fasting, there are nice 数据 showing improvements in the gut microbiome 和 in particular, in the treatment of irritable bowel syndrome 和 other forms of colitis in time-restricted feeding, meaning time-restricted feeding seems to be able to assist 人们 与 那些 conditions following the general parameters 那 I discussed 之前 eight 小时 和 so forth. Why 和 how? Well, by way of intermittent fasting impacting the expression of 这些 various clock genes 和 因为 the clock genes impact the mucosal lining, the mucus lining of the gut. It appears 那 intermittent fasting 可以 减少 the amount of so-called lactobacillus 那's present in the gut. 和 lactobacillus, when in high 水平, is correlated 与 a number of 不同的 metabolic disorders. At the same time, time-restricted feeding seems to 增强 the proliferation of some of the gut microbiota like Oscillibacter 和 some of the other ones 那 promote healthy mucosal lining 和 那 promote better overall intestinal function.

安德鲁·休伯曼：

这些 are 通路 那 have now been established, 和 it appears 那 intermittent fasting isn't just modulating 这些 processes 但 is actually having a direct effect on the mucosal lining in a way 那 favors a healthier gut microbiome. So it 应该 come as no surprise 那 many 人们 who experience gut issues benefit 从 restricting their feeding window to eight 小时 或 so per every 24-小时 period. The other 非常 exciting finding 关于 intermittent fasting is 一 of the major health issues 这些 天 is the proliferation of so-called nonalcoholic fatty liver disease. 30 years 或 so, nonalcoholic fatty liver disease was exceedingly rare to see in the clinic except in alcoholics. Fatty deposits in the liver are bad. It is 本质上 liver disease. Nowadays, children 和 adults are showing up 与 nonalcoholic fatty liver disease. Some of 这些 人们 are obese, others are not, 但 it's a serious health concern, 和 it's growing in numbers all the time.

安德鲁·休伯曼：

A recent 研究 那 was published in Cell Reports Medicine just a couple 周 ago tested the hypothesis whether 或 not the gut microbiome 或 so-called 棕色脂肪 组织 is impacting the liver health 和 in particular, nonalcoholic fatty liver disease. The short takeaway 从 这 研究 is 那 contrary to what was previously thought, the gut microbiome, while 非常 重要 对于 a number of other processes in the 身体, doesn't seem to be related to 这 nonalcoholic fatty liver disease. 这 is surprising to 人们 或 应该 be to 那些 of 你 那 have been following the gut microbiome literature. 然而, 棕色脂肪, which is a healthy fat 那 我们 have between 我们的 二 scapulae 和 in 我们的 upper neck, it doesn't tend to be blubbery-type fat pads, 但 it sits deep to the 皮肤 但 creates a thermogenic effect in the 身体 那 is helpful 对于 减少 the amount of other fat, the type of fat 那 我们're 更多 通常 used to thinking 关于 和 talking 关于, white fat 和 pink fat, 那's subcutaneous fat 大约 the abdomen 和 so forth.

安德鲁·休伯曼：

棕色脂肪 seems to have a direct correlation 与 the lack of nonalcoholic fatty liver disease. What 这 研究 showed was 那 in 人们 那 have diminished concentrations of 棕色脂肪, there is a higher probability of having nonalcoholic fatty liver disease. Now, the good news is 棕色脂肪 stores 可以 be 增加了. 和 again, 这 isn't going to create blubber of 棕色脂肪. 这 is going to create 增加了 thermogenesis 和 actually make 人们 leaner, 和 棕色脂肪 has a number of other 重要 positive effects. Now, 这 is interesting 因为 冷暴露 of anywhere 从 一 to 三 分钟, 二 或 four times per 周, 或 maybe even 10 分钟, 二 to four times per 周, 可以 增加 棕色脂肪 stores.

安德鲁·休伯曼：

Also, time-restricted feeding has now been tied to the density of 棕色脂肪 stores. So time-restricted feeding also seems to positively 增加 棕色脂肪 stores, probably 因为 of the way 那 棕色脂肪 stores relate to 肾上腺素 和 肾上腺素, which tend to go up when 我们're fasted. What does 这 all mean? 这 means 对于 sake of liver health 和 对于 sake of 减少 或 maybe preventing 或 even potentially, want to underline potentially, reversing nonalcoholic fatty liver disease, time-restricted feeding also appears to be beneficial. Many 人们 out there are interested in optimizing their 激素. 和 as 我们 mentioned earlier, insulin is a 激素 和 time-restricted feeding seems to have 非常 positive effects on overall insulin profiles 和 so forth. 但 anytime 你 mention 激素, 人们 immediately seem to leap to the sex steroid 激素, testosterone 和 estrogen, 因为 indeed they have powerful effects both in the short term 和 the long term, in terms of 我们的 mental 和 physical 健康与表现. There's at least 一 研究 那's explored the effects of time-restricted eating on 表现, athletic 表现, 免疫 function, 和 身体 composition. 这 was a 研究 by Moro et al. 那 was performed on elite cyclists. So I want to point 那 out. It was a randomized control trial, 但 what's 确实 nice 关于 这 研究 is 那 it explored a number of 不同的 hormonal parameters in 人们 那 were using time-restricted eating 或 那 had a 更多 extended eating window.

安德鲁·休伯曼：

和 they tracked everything 非常 carefully. 和 the amount of food they were eating was actually pretty considerable. 4,800 calories. So 那's a lot of calories. 但 then again, they were 非常 active. 和 they measured a number of 不同的 things related to vo2 max, etcetera. 表现 和 overall 表现 at what they did, cycling, is not the point 那 I want to emphasize here. 尽管 there were some positive effects on their 表现 related to time-restricted eating. The point I want to talk 关于 relates to things 那 presumably relate to most everybody, which are the effects on things like glucose, thyroid 激素, testosterone, sex 激素 binding globulin, which 可以 bind up testosterone 和 prevent the so-called free form of testosterone, which is the 一 那 has most of the actions in the 大脑和身体.

安德鲁·休伯曼：

和 the major takeaway 从 这 研究 was 那 time-restricted feeding of the same amount of calories as the so-called control condition, okay? Same calories, 但 either compact throughout the 24-小时 cycle to an eight-小时 feeding window 或 allowing them to eat over a larger feeding window, did lead to significant 降低 in free testosterone. 和 I think a number of 人们 会 raise their eyebrows to 那 和 think, oh, well then maybe time-restricted feeding is not 对于 me.

安德鲁·休伯曼：

There are a number of 重要 considerations of course. 一 is while the 降低 in free testosterone was significant, it's also going to depend on where 人们 start out. So if somebody has already low 或 modest 水平 of testosterone 和 it drops by 10 或 20%, 那 could lead them 进入 a state of poor 表现 和 wellbeing. Whereas if somebody has higher testosterone, a 降低 won't necessarily do 那. So it's 重要 to take 那 进入 consideration. 这 is why I'm 总是 such a fan of 人们 doing their 血液 work 和 knowing what's going on under the hood 对于 them. A 非常 interesting change in hormonal profile was cortisol, so-called 压力 激素. Cortisol, of course, is also naturally 释放了 early in the 天 in a healthy way to wake 你 up 和 promote alertness, 但 你 don't want its 水平 to be too high 或 to have peaks in cortisol late in the 天. It's actually correlated 与 depression 和 a number of other untoward things.

安德鲁·休伯曼：

I 会've thought 那 by restricting a feeding window to a particular time each 天, 那 这些 hard 训练 cyclists 会've undergone 增加 in serum cortisol. 和 in fact, the opposite was true. They had significant reductions in serum cortisol as a consequence of time-restricted feeding. I 应该 mention there were significant reductions in serum cortisol also in the control group, 但 not to the same extent. 和 the 二 groups did differ significantly 从 一 another. Now 这 is 重要 因为 if 你 just look at 一 激素, testosterone, 你'd say, okay, based on 这些 数据, time-restricted feeding is 减少 testosterone 水平 significantly, even though the number of calories is quite high 和 is held constant across the 研究.

安德鲁·休伯曼：

但 in fact, 因为 cortisol is lower, it may mean 那 the effects of testosterone, 或 the reduction in testosterone, is offset. 和 那's 因为 cortisol 和 testosterone are 总是 in 这 somewhat of a dance in terms of cortisol inhibiting the effects of testosterone largely 和 vice versa. So it is interesting 和 重要 to look at the total gallery of 激素. 和 they did look at a number of 激素. They looked at other 炎症性的 markers. 那些 were not 增加了. 那's not surprising. If 你 remember back to the 2012 Satchin Panda 研究, 这 early pioneering 研究 on time-restricted feeding, they saw reductions in 压力 激素 和 in 炎症性的 markers in time-restricted feeding mice. 和 here 这 also seems to be the case in humans. So the takeaway is, 对于 sake of 激素 health, time-restricted feeding is compatible 与 quality 激素 health, even in high performing athletes.

安德鲁·休伯曼：

Based on everything 我们 know 和 那 我们've discussed, I 会 not suggest 那 人们 restrict their feeding window to 更少 than eight 小时, 尤其是 if they're 训练 hard on a regular basis. 和 it's not just athletes 那 应该 pay 注意力 to 这. When 我们 are working 非常 hard, when 我们 are psychologically stressed, when 我们 are studying 对于 exams, 或 我们 are in conflict 与 somebody on a regular basis, 那 creates a 压力 in the 身体 那's 非常 相似的 to 那 of physical 训练. The 身体 和 大脑 don't distinguish between physical 压力 和 mental 压力. It's all 神经系统. Remember 那, it's just cortisol 和 肾上腺素. There's no special 激素 just 对于 physical 压力 versus psychological 压力. So again, in thinking 关于 what sort of feeding window 会 be right 对于 你, 我们 arrive back at 这 eight-小时 time bin 那 seems 更多 或 更少 flexible 对于 most conditions, even high performing elite athletes. 和 I 会 say just biological extension, even 对于 人们 那 have a lot of 压力 in their life.

安德鲁·休伯曼：

和 I personally wouldn't suggest 那 人们 who have a lot of 压力 in their life 或 the potential 对于 压力 in their life shorten their feeding window much shorter than eight 小时 因为 then 你 会 expect 那 你 会 start to 增加 some of the 炎症性的 markers, 你 会 增加 the 压力 激素, 和 你 会 be decreasing things like testosterone 和 estrogen, some of the sex steroid 激素. So again, it's all 关于 context 和 the eight-小时 window. It isn't holy, 但 seems to be a 确实 useful guide to extract the great health benefits, of which there are many, in, of which 我们've discussed 从 intermittent fasting, time-restricted feeding, 和 yet 那 it could still be compatible 与 decent social schedules 和 对于 maintaining 激素 health.

安德鲁·休伯曼：

In keeping 与 这, 对于 women 那 are trying to maintain ovulatory cycles 或 对于 couples 那 are trying to get pregnant, I think it's also 重要 to not create a feeding window 那's too short. The relationship between feeding, 和 身体 fat stores, 和 glucose, 和 leptin, 和 激素 is a well-established 一. 和 我们 可以 summarize it 非常 easily here, 尽管 I've done several episodes related to 这 previously on optimizing 激素 health. 但 basically 我们 undergo puberty when there's enough food 和 there's enough 身体 fat 那 the 身体 fat sends a signal to the 大脑 called leptin. 那's a 激素 那 comes 从 身体 fat, signals to the 大脑 to turn on puberty. 那's puberty, 但 even as adults, 对于 women 那 are menstruating, there needs to be sufficient leptin signaling to the 大脑 in order to maintain ovulation 因为 of the way 那 the 大脑 communicates 与 the pituitary 和 the ovaries.

安德鲁·休伯曼：

Similarly, 对于 men, fasting, 或 extreme 运动 plus fasting, 我们 now know 减少 testosterone. Its impacts are not exactly clear. 然而, if 你 减少 food intake, either in total calories 或 in duration too much, 你 会 suffer a drop in sperm count; fertility 会 drop. 和 这 makes sense. The 身体 is communicating to the 大脑 whether 或 not conditions are sufficient in the 身体 to reproduce 和 to presumably 和 hopefully support the health 和 wellbeing of 那些 offspring. So there's a logical link between 身体 fat 和 eating 和 how much food is available to 你 和 how long it's available to 你. 和 the signals in the 大脑 那 allow 对于 reproductive success. There are some 数据 那 point to differences in the effects of intermittent fasting 对于 males versus females. 那些 数据 right now only come 从 mice. 那 研究 was published by Satchin Panda recently.

安德鲁·休伯曼：

我们 still await the 研究 in humans. Some 人们 do not do well on intermittent fasting either in terms of 情绪 或 激素 health. 和 so everyone needs to determine 对于 themselves whether 或 not having a time-restricted feeding window is good 对于 them. How long 那 time-restricted feeding window 应该 be. I think eight 小时 is kind of a nice minimum to adhere to based on everything 那 我们've covered today. 和 对于 some 人们, time-restricted feeding is not going to be compatible 与 激素 health 对于 them. 对于 them eating 更多 meals spread throughout the 天, presumably smaller meals, same caloric intake, is going to be 更多 beneficial 对于 their 激素.

安德鲁·休伯曼：

这 is something 那 is going to be individual 和 is going to have to be determined on an individual basis. 然而, if 你're going to try time-restricted feeding, I do want to remind 你 那 taking a period of 三 to seven, 或 ideally 10 天 to transition 进入 it, not just going flipping 从 eating to 三 meals a 天 那 span 从 6:00 AM to 10:00 PM 和 suddenly going to an eight-小时 feeding window, 但 rather winnowing down 那 feeding window 关于 an 小时 或 so per 天, is going to allow the 激素 系统 of 你的 身体, including leptin, the hypocretin orexin 系统, which are 系统 within the 身体 那 signal to the 大脑 那 food is 关于 to come. Allowing 那些 系统 to adjust so 那 你're not overwhelmingly hungry, irritable, 和 你're not throwing 你的 whole 激素 系统 out of whack.

安德鲁·休伯曼：

I keep coming back to 这 eight-小时 feeding window 和 I want to provide a little 更多 basis 对于 it 和 just to encourage 那 it's not completely arbitrary. The lengthy review 那 I mentioned earlier features a number of 研究 那 have used 这 eight-小时 feeding window, 但 there's a particular 研究 那 I'd like to highlight, mainly 因为 I don't expect 人们 to delve 进入 the full reference list of the other review. 和 这 is a 研究 那 was carried out between Satchin Panda's lab 和 Chris Verity's lab. So 这 is a collaboration. The 研究 was carried out in humans 和 is entitled "Effects of eight-小时 time-restricted feeding on 身体 weight 和 metabolic disease risk factors in obese adults," excuse me. 和 这 研究 本质上 showed, I'll just read the conclusions, 那 an eight-小时 time-restricted feeding produces a mild caloric restriction 和 weight loss 没有 calorie counting.

安德鲁·休伯曼：

So 那's key, right? 这些 人们 aren't calorie counting. Somehow just by adhering to an eight-小时 window, they are taking in fewer calories than they're burning off 和 clinically it reduced 血液 pressure. So I mentioned the 研究 not 因为 there aren't many others involving the eight-小时 feeding window also in humans, 但 因为 the eight-小时 feeding window has been tested in obese adults 和 non-obese adults. 和 there are even a few 研究 in children. So 这 eight-小时 window seems to be a 确实 good rule of thumb 和 a kind of anchor 大约 which 我们 可以 each think 关于 incorporating time-restricted feeding. There are of course other patterns of feeding 和 while some 人们 have engaged in longer fasts of 24 小时, 36 小时, 或 更多, alternate-天 fasting, meaning eating 一 天 not eating the next 天, 或 in some cases eating 一 天 和 eating 非常 few calories, 500 或 600 calories the next 天, has been tested.

安德鲁·休伯曼：

A few 研究 have also looked at eating a sort of maintenance 水平 of calories 对于 five 天 和 then taking 二 天 和 fast 和 clear 通过, 或 eating 非常 few calories, 300 或 500 calories. In fact, there's a sort of a community online of 人们 那 are exploring longer fast 对于 sake of trying to offset dementia 或 reverse effects of dementia. Thus far, at least in my awareness, there isn't any quality clinical peer-reviewed 研究 on 那 yet, 对于 sake of dementia, 尽管 I await 那些 研究 和 if anyone's aware of them, please send me a link in the comments. 但 alternate 天 fasting has gotten the so-called safe bill of health. 这 has been written up, meaning 那 人们 didn't suffer bone loss, they didn't suffer any major detrimental effects. It does seem 那 it 可以 create significant weight loss 和 可以 help 与 obese 个体, 那 it 可以 减少 resting 血液 glucose, 和 every other 天 fasting, in many cases, 可以 produce 更多 rapid effects on weight loss 和 reductions in 血液 glucose than time-restricted feeding.

安德鲁·休伯曼：

然而, every other 天 type fasting 对于 most 人们 is not going to be feasible. They're just not going to be able to do 那 对于 a long period of time. 和 what hasn't 确实 been done is the follow up to see whether 或 not 人们 who do every other 天 fasting 或 five 天 of eating, followed by 二 天 of fasting, whether 或 not 那 leads to a rebound in weight gain, whether 或 not 那 leads to a rebound in 血液 glucose, etcetera. So 对于 now, the eight-小时 feeding window 和 time-restricted feeding seems to be the most tested, supported in animal 研究 和 in human 研究, 和 the 一 大约 which I think most 人们 应该 orient if they're considering getting 进入 time-restricted feeding.

安德鲁·休伯曼：

It's also sort of hard to imagine how 一 could include a significant 运动 schedule, 或 work schedule, on every other 天 fasting. Remember, in any 研究 人们 are 经常 being compensated 或 at least are incentivized in some way to adhere to the 研究. 这 is 一 of the major issues 那 I have 与 any 研究 那 says 那 三 或 four 不同的 diets are 本质上 equal in terms of their ability to produce weight loss. Adherence is 非常 不同的 in the outside world where 你 don't have a researcher monitoring 你, where 你're not logging all 你的 food. Most 人们 don't do 那 consistently. 和 我们 可以 take a little bit of a neuroscience perspective on 这 to try 和 arrive at what the best kind of organization of an eating plan, 或 if 我们 wanted to call it a diet 我们 could, 会 be 对于 你.

安德鲁·休伯曼：

Many 人们 find it easier to just not eat 对于 certain periods of each 24-小时 cycle than to eat smaller portions. Portion control is 非常 hard 对于 some 人们. 对于 other 人们 it's manageable. 但 人们 like me, I don't eat half the croissant. I don't think it's a real thing. It's not available to me, I 应该 say. Now of course I could eat just half a croissant, 但 I notice 那 when I eat the croissant 因为 they're so delicious 那 it creates a rise in 血液 glucose, a rise in the other 激素 和 chemicals 那 are associated 与 ingesting delicious, highly palatable food. 和 it's actually a lot of work 对于 me to just eat half the croissant. There's something 那's much 更多 thoroughly satisfying 关于 eating the entire croissant. 和 actually there's something 那's somewhat satisfying 关于 not eating the croissant at all 和 just knowing 那 later I 可以 eat the whole croissant.

安德鲁·休伯曼：

Now 那's me. Other 人们 find 那 they don't have any trouble 与 portion control. 那 对于 them just eating small bits of food throughout the 天 is what sets them in the right psychological 和 physical state 对于 sake of work, etcetera. 和 I mentioned work 和 mental 专注 因为 一 of the aspects of fasting 那 [has] drawn a lot of 人们 to time-restricted feeding 和 fasting is the clarity of 心智 那 人们 get when, 首先 of all, they don't have to think 关于 when they're going to eat 因为 they know when their eating window begins. They also don't have to think 关于 regulating their behavior 因为 they already know when they're going to eat 和 when they're not going to eat. Whereas when 你're restricting portions, 你 actually have to make decisions all the while. 和 I think I, like many 人们, decide, well is 那 exactly half 或 could I have another rung on the croissant? 这 kind of thing.

安德鲁·休伯曼：

I don't negotiate 与 food. 那's why I like a time-restricted feeding window. I know I'm going to eat 对于, in my case, I use a 10-小时 feeding window 或 so 和 I'll eat the whole croissant. I just don't have to think 关于 it. Now the food choices 那 你 make inside of 那 feeding window are of course also going to be 非常 重要. Certain foods 会 增加 血液 glucose such 那 你're going to get hungrier 和 hungrier. Others 会 maintain lower 血液 glucose 和 会 allow 你 to be 更多 controlled in the foods 那 你 pursue. 那些 are all individual considerations 那 are deserving of their own entire episode. 但 I do want to point out 那 the advantage of time-restricted feeding is 那 it involves a lot of the decision-making in the 大脑. The so-called go, no go circuitries of 我们的 basal ganglia, if 你 want to know 那些 areas 那 control them. Anytime 我们 have to restrict a behavior 那's called a "no go." Anytime 我们 engage in a behavior 那's a "go." No go behaviors require a lot of what's called top-down control 和 it's 非常 metabolically demanding. 和 so time-restricted feeding allows 你 to part 从 the whole no go, go negotiation 那 你 have to undergo when 你 have to restrict portions. 和 so I think 这 is a reason why many 人们 have gravitated towards time-restricted feeding 和 why 对于 人们 那 don't want to have to think 关于 all 那, it's just 非常 straightforward. 一 of the 更多 hot button issues out there is whether 或 not, given equal amounts of caloric intake 和 equal amounts of activity 和 equal amounts of nutrients, etcetera, whether 或 not restricting food to a particular window biases 更多 weight loss toward fat loss versus loss of other 组织.

安德鲁·休伯曼：

因为 of course when 我们 lose weight, 我们 可以 lose 那 从 any number of 不同的 storage sites within the 身体: 肌肉, 水, glycogen, 或 fat. Now 这 is such a hot button issue 那 I almost don't want to get 进入 it, 但 I'm going to get 进入 it anyway 因为 there are 数据 那 are 非常 interesting. 这 is covered in the review 那 I mentioned earlier 那 describes how if 人们 follow a time-restricted feeding schedule 对于 long periods of time, so 60 天 或 longer, there'[re] some metabolic changes in the way 那 人们 metabolize 能量 那 do seem to shift the 系统 toward 更多 fat loss relative to burning of other 组织 when in a state of caloric restriction, 和 I want to say when in a state of caloric restriction 因为 there's 确实 no way to cheat the 系统, there's no way 那 你 可以 ingest far 更多 calories than 你 burn 或 excrete.

安德鲁·休伯曼：

When I say excrete, I certainly don't suggest 这, 但 bulimics 和 other 人们 那 have eating disorders 会 use laxatives as a way to eliminate food quickly 从 their 系统 so it 可以't be converted 进入 fat 或 other forms of 能量. 那's a 非常, in 那 case, it's a pathological situation. 但 in general, calories in versus calories out, as I mentioned earlier, is 这 kind of foundational element. 但 in states of caloric restriction, meaning submaintenance intake, time-restricted feeding does seem to bias 更多 of the 能量 burned to compensate 对于 那 deficit 从 fat. 和 the way it accomplishes it is 非常 interesting. It turns out 那 it drives 更多 fat loss by way of increasing a hepatic lipase. 这 is something called L-I-P-C, hepatic means of the liver 和 lipase, which anytime 你 hear A-S-E means it's an enzyme.

安德鲁·休伯曼：

So it seems to 增加 hepatic lipase. So it 增加 the enzyme 那 metabolizes fat 对于 lipolysis 和 能量 production 和 减少 something called CIDEC, C-I-D-E-C, which is a lipid droplet associated an lipolysis inhibitor. Now 那's a mouthful, no pun intended. 但 what CIDEC 确实 is, 这 lipid droplet associated molecule, is it 可以 inhibit lipolysis. So extended periods of time-restricted feeding, meaning eight-小时 feeding window, 或 10-小时 feeding window, 那's obeyed 对于 several months 或 更多 seems to allow the 系统 to shift toward burning 更多 fat 或 rather using a higher percentage of fat when in a caloric deficit. Now I doubt 那 这 is going to resolve the truly barbed wire, almost hairball ridiculous online debates 关于 whether 或 not time-restricted feeding is better than another feeding schedule. Look, I don't think any particular feeding schedule is holy.

安德鲁·休伯曼：

If 你 are subcaloric, meaning fewer calories burned than calories ingested, 你're going to lose weight. 但 the 数据 seem to point to the fact 那 if 你 do time-restricted feeding 对于 a fairly long duration of time 和 你 maintain 那, 那 你 are increasing 这些 lipases 那 增加 lipolysis, 能量 use 从 fat, 和 你 are decreasing the lipid droplet associated lipolysis inhibitors. So it's both 你're removing the break 和 你're pressing on the accelerator of fat loss. 和 I think 那 这 logically points to a case in which using time-restricted feeding 与 a subcaloric intake seems to be, at least to my 心智, the most scientifically supported way to ensure 那 a significant portion of the weight 那 一 loses is 从 身体 fat stores. Any discussion 关于 fasting 会 be incomplete 没有 a discussion 关于 what does 和 does not break a fast.

安德鲁·休伯曼：

然而, there is no black-和-white answer to 那 question 和 你 应该 immediately understand why. It's 因为 eating 和 not eating are not equivalent to fed 和 fasted. It depends on when 你 ate, how much 你 ate, 和 where 你 are in 你的 circadian cycle. 我们 可以 actually arrive at a simple answer to whether 或 not something breaks the fast 或 not. Now the technical way to go 关于 这 会 be to wear a continuous glucose monitor 和 to ingest little bits of food of 不同的 kinds 或 large amounts of food of 不同的 kinds, 和 measure 血液 glucose 因为 ultimately 血液 glucose is the readout of whether 或 not 你的 系统 is in a fed 或 fasted state. There are other parameters too, of course, 但 那's the dominant 一.

安德鲁·休伯曼：

Insofar as the scientific literature says, drinking 水 会 not break 你的 fast. Drinking tea 会 not break 你的 fast. Drinking coffee, provided it is black coffee, 会 not break 你的 fast. Ingesting caffeine in pill form 会 not break 你的 fast. There are other things 那 won't break 你的 fast. 对于 instance, eating 一 peanut when deep in a fasted state 会 not break 你的 fast. Eating a whole handful of peanuts 可能 not even break 你的 fast if 你 are in a 非常 low glucose state. 然而, if 你 just finished a meal 那 included carbohydrates 或 it was a 非常 large meal of any kind an 小时 ago, yes indeed, eating 一 peanut could break 你的 fast. So it's all contextual. 那's what's 确实 重要 to understand unless 你're going to wear a continuous glucose monitor 和 unless 你're going to wear a continuous glucose monitor 和 set an absolute numerical threshold 对于 what it is to break 你的 fast, I think there are some simple rules 那 我们 可以 follow.

安德鲁·休伯曼：

首先 of all, anything 那 involves sugar, in particular simple sugars, 可以 potentially break 你的 fast. 和 there's actually a 研究 on 这 which shows 那 if 人们 ingest even 一 gram of sugar post dinner, if they had a full meal 对于 dinner, 那 可以 actually disrupt the expression of some of the circadian genes related to fasting 和 to sleep 和 sleep-related fasting. Now 那's pretty extreme, it's almost kind of scary to think 关于, 但 那's how sensitive 我们的 系统 is if 我们 already have somewhat elevated 血液 glucose 从 a meal 那 我们 ate an 小时 或 so ago. Whereas if 我们 have run 对于 an 小时 或 trained hard, high-intensity 训练, 和 我们 haven't quite reached the beginning of 我们的 so-called feeding window, 会 eating a small amount of food take us out of 那 fast? Well, depends on what the food is.

安德鲁·休伯曼：

If it's mostly fat, probably not. A number of 人们 out there nowadays talk 关于 so called fat fasting. Fat fasting is a way to kind of wriggle past the stringency of either eating 或 not eating as a black-和-white rule 对于 feeding window versus non-feeding window. So some 人们 会 ingest medium chain triglycerides, so-called MCTs, 或 人们 会 ingest fats only until their official feeding window begins. So 这些 are sort of how the negotiations 那 人们 carry out tend to go. 但 fat of course won't 增加 血液 glucose 和 insulin as much as carbohydrates 会. Protein 会 have sort of an intermediate effect. 和 as I mentioned earlier, ingesting carbohydrates 与 some fat 会 tend to blunt the rise in glucose 和 会 extend the duration over which glucose is 释放了. So 我们 确实 可以't say food X 或 beverage X breaks a fast.

安德鲁·休伯曼：

然而, at the extremes 我们 可以 say 那. 对于 instance, if 你 drink a 可以 of soda pop, unless 你 just ran an ultra-marathon, 你're breaking 你的 fast, okay? 你 eat a piece of pizza, 你're breaking 你的 fast. If 你 eat purely fats, maybe, probably not if 你've been fasting 对于 five 小时 或 更多, strictly fasting 对于 five 小时 或 更多. So 你 可以 start to see where there's a lot of wiggle room 和 it's 非常 contextual. 和 这 is why any post 那 你 see 或 any information 那 你 see 那 something does 或 does not break 你的 fast 那 doesn't place it in the context of when the last time 你 ate 和 what 你 ate 和 你的 activity 和 你的 time within the circadian clock schedule of 24 小时, it's a sort of meaningless discussion. So in general, I think what's 确实 useful, if 你're not going to wear a continuous glucose monitor, is to try 和 be fairly strict 关于 when 你 initiate 你的 feeding window 和 when 你 stop 你的 feeding window.

安德鲁·休伯曼：

和 as time evolves 和 你 establish a 更多 regular routine of eating certain kinds of foods, 和 not others, 那 are right 对于 你. 因为 as I've emphasized 之前 on 这 podcast, 和 I 会 continue to emphasize, keto works great 对于 some 人们. Vegetarian keto works great 对于 some 人们. Carnivore diet works great 对于 other 人们. Some 人们 are omnivores, some 人们 are carnivores, some 人们 are vegan. All of 那 is great 和 fine by me. Everyone has to establish what's right 对于 them. Today 我们've 确实 bypassed the discussion 关于 foods of a particular origin 或 type, animal based 或 plant based, 但 all the same rules apply within 这 thing 那 我们 call intermittent fasting 或 time-restricted feeding. So what breaks a fast 会 depend. 和 what 你 want to eat 或 what 你 are willing to eat, 那's a totally separate manner 从 when 你 eat.

安德鲁·休伯曼：

但 as 我们've established, when 你 eat is vitally 重要. Some of 你 are probably wondering whether 或 not artificial sweeteners 或 non-artificial plantbased sweeteners like stevia break a fast. 这 会 vary somewhat, 和 I have to say the 数据 on 这 are somewhat mixed. There is 证据 那 when 人们 ingest artificial sweeteners 那 it 可以 create a transient 增加 in 血液 glucose followed by a transient 降低 in 血液 glucose below baseline. 这 is thought to explain the 增加 in hunger caused by ingestion of things like aspartame 和 sucralose 和 things of 那 sort. There are not a lot of good 研究 exploring the plantbased nonsugar sweeteners.

安德鲁·休伯曼：

Things like stevia, even things like monk fruit, which is a separate category 进入 itself; there aren't a lot of 研究 on 这. I think most 人们 need to establish 这 对于 themselves. The best way of course 会 be to wear a continuous glucose monitor, to go 进入 a fasted state of either 一 小时 或 二 小时, 或 maybe 你've been fasting all 夜间 和 then ingest stevia in whatever form 你 want 或 coffee in whatever form 你 want 与 sucralose 或 aspartame, etcetera. Setting aside the discussion 关于 the effects of 这些 things on the gut microbiome, which is a 不同的 topic entirely, I think it's fair to say 那 in moderation, the plant-based nonsugar sweeteners like stevia, in particular stevia seems to have a minimal impact on overall 血液 glucose when considered over a fairly large time bin.

安德鲁·休伯曼：

Aspartame 和 sucralose, saccharin, I think 我们 可以 say 更多 或 更少 the same, 但 as soon as 你 get 进入 a discussion 关于 那些, 你 also have to get 进入 a discussion 关于 some of the 证据 published in Nature 和 other excellent journals now pointing to the fact 那 when consumed in excess, not when consumed in moderation, 但 when consumed in excess, 那 那些 可能 have some detrimental effects on the gut microbiome. So do artificial sweeteners break a fast? Depends on the amount. Depends on the type. 和 in general, I think 你're probably okay provided 那 你're not indulging in them too 经常. 然而, some 人们, just by virtue of tasting something sweet, feel a spike in their appetite 那 makes it harder 对于 them to adhere to the feeding window.

安德鲁·休伯曼：

和 so 这 is why 你 可以 imagine 那 a 确实 well-controlled 研究 on 这 会 be 非常 hard to carry out, 和 I'm not 确实 sure 那 it's worth 我们的 tax dollars to actually design 和 carry out a 研究 like 那 因为 there 会 be so much individual variation in terms of discipline, in 那 adhering to the feeding window, whether 或 not 人们 experience 增加 in drops in 血液 glucose, how 那 impacts them, whether 或 not they're exercising. It just becomes an infinite variable space, as 我们 say in experimental science.

安德鲁·休伯曼：

So 你 确实 have to determine 那 对于 你. 但 I don't think 那 我们 可以 fairly say 那 artificial sweeteners break a fast. I think 那 会 be incorrect to say.

安德鲁·休伯曼：

Earlier 我们 were talking 关于 glucose disposal agents, both behavioral 和 compound based, things like metformin 和 berberine, 和 in fact, cinnamon is even a mild glucose disposal agent. It 可以 actually 减少 血液 glucose. Lemon 和 lime juice, believe it 或 not, 可以 lower 血液 glucose. 你 may have experienced 这 之前 of eating something 非常, 非常 sweet 和 almost feeling kind of overwhelmed 和 kind of poisoned by how sweet it is, 尤其是 if 你're not accustomed to eating a lot of sugary things.

安德鲁·休伯曼：

一 quick remedy 对于 那 is actually a half lime 或 half lemon squeezed 进入 juice 和 drinking 那, just by virtue of the taste 和 by virtue of the fact 那 it 会 减少 血液 glucose, 你'll notice 那 那 effect almost immediately disappears. 那's not magic, 那's the effects of acidity on 血液 glucose 水平. So there are a number of things 那 可以 adjust 血液 glucose. They're not necessarily disposal agents, they're not sweeping it out of the bloodstream in the same way 那 berberine 或 metformin 会 或 那 high intensity 运动 at the appropriate times of 天 会.

安德鲁·休伯曼：

但 there is 一 particular thing 那 一 可以 ingest 那 可以 help manage psychologically 和 表现-wise 通过 the fasting portion of the intermittent fasting 和 get 你 to 你的 feeding window, 和 那's salt. I've talked a little bit 关于 这 on the podcast 之前, 但 因为 neurons use salt, sodium, 和 potassium 和 magnesium, the so-called electrolytes, in order to perform their magic of chemical 和 electrical signaling, everything 你 do depends on chemical 和 electrical signaling, 和 all 那 chemical 和 electrical signaling requires electrolytes in some form 或 another.

安德鲁·休伯曼：

Neurons run on the passage of ions like sodium in 和 out of their cell membranes, 或 I 应该 say across their cell membranes to be accurate. Many 人们 find 那 the kind of lightheadedness, the shakiness 那's accustomed 与 having slightly low 血液 sugar 可以 be offset by taking a half teaspoon 或 so of sea salt 或 even just a tiny pinch of salt 和 putting it 进入 some 水 和 drinking it.

安德鲁·休伯曼：

Some 人们 find 因为 of the glucose lowering effects of acidity, 那 if they're feeling kind of shaky 和 not well 和 they put some lemon juice 进入 水 和 drink 那, it drops their 血液 glucose further. So there's a common practice nowadays 那's discussed on the internet of waking up, drinking some 水 与 some lime 或 lemon juice in it 与 a little pinch of salt. I think 那 little pinch of salt is a good idea. What is it doing? How is it offsetting all 这?

安德鲁·休伯曼：

Well, salt 水 actually has a mild effect as a glucose disposal agent, 但 it has a stabilizing effect on 血液 volume. 和 so 因为 sodium brings 与 it 水 和 the so-called osmolarity of 你的 血液 和 你的 身体 depends on the salt 水平 in 你的 血液 和 大脑和身体, many 人们 find 那 if they're feeling shaky, they're feeling lightheaded, they 可以't concentrate, they think they need sugar 或 food, 但 what 会 actually remedy 那 is some salt.

安德鲁·休伯曼：

和 I know a number of 人们 那 have incorporated 这 practice 和 have written to me 和 saying, "Oh, if I just take a little bit of salt 和 some 水," they may 或 may not include the lemon 或 lime juice, they immediately feel better 和 find 那 it's actually quite straightforward to get out to 那 ... to wait until the feeding window kicks in.

安德鲁·休伯曼：

这 is 尤其是 true 对于 人们 那 are using caffeine 因为 when 你 ingest caffeine, 你 actually excrete a lot of 水 as a diuretic effect 和 与 那 水 goes salt, so it actually causes 你 to excrete sodium. Now the role of sodium in 血液 pressure 和 hypertension is quite controversial.

安德鲁·休伯曼：

Science Magazine, 一 of the premier scientific journals out there, had a special issue all 关于 salt some years ago talking 关于 the 研究 大约 hypertension. Indeed, 人们 与 chronic hypertension 或 high 血液 pressure 或 非常 high 血液 pressure in particular, 应该 be wary of ingesting too much sodium, 但 对于 most 人们 ingesting sodium, provided they drink enough 水 和 they don't have chronic hypertension 或 high 血液 pressure, is actually beneficial.

安德鲁·休伯曼：

那 doesn't mean 你 应该 be drinking sea 水, doesn't mean 你 应该 be overindulging in salt, 但 many 人们 find 那 they 可以 manage their mental 和 physical state 和 even feel 确实 terrific, real clarity of 心智 和 确实 enjoy their fast when they're ingesting sufficient salt. 和 all it requires 确实 is a small pinch of salt, ideally Himalayan 或 sea salt if 你 want to get fancy 关于 it, 但 table salt 会 be fine, 和 just drinking 那 in some 水, maybe 与 lemon 或 lime juice to offset the taste a little bit, 可以 确实 stabilize 一's jitters 和 可以 stabilize the 心智.

安德鲁·休伯曼：

和 你 可能 also notice 可以 offset 那 churning 和 yearning in appetite where 你 可以't imagine going another five 分钟 之前 eating something, suddenly 你 feel okay. 和 那 has to do 与 a lot of the effects of 血液 volume caused by ingesting salt in the appropriate amounts. In other words, sometimes 你 think 你 need food, 但 what 你 确实 need is salt 和 salt 可以 make 你 feel better immediately.

安德鲁·休伯曼：

I'd like to mention 二 excellent zero-cost resources if 你're going to explore time-restricted feeding 或 maybe if 你 already are doing time-restricted feeding. I have no affiliation to either of 这些. The 首先 is the website 那 I mentioned 之前, My Circadian Clock, which is the website hosted by Satchin Panda 和 colleagues. There are a lot of resources there where 你 可以 log 你的 food intake, get information 关于 time-restricted feeding, all the science, the ongoing 研究, etcetera.

安德鲁·休伯曼：

The other is the so-called Zero app 那 makes it 非常 easy to mark when 你're beginning 你的 feeding window 和 when 你're ending 你的 feeding window. 和 in so doing, marking when 你 are beginning 你的 fast 和 ending 你的 fast 或 at least initiating the beginning of the unfed state as 我们 could 更多 accurately call it.

安德鲁·休伯曼：

It's a terrific app. I've used it 从 time to time. I don't tend to use it in an ongoing basis 因为 I'm just sort of used to eating in a particular time of 天 now, 但 anytime I've shifted 那 window, 对于 instance, a few 周 ago, I started moving 那 protein intake in my entire feeding window earlier in the 天. 和 因为 那 takes some 注意力 on my part, 因为 I'm not used to doing 那, I've been using the Zero app 和 I like it quite a lot.

安德鲁·休伯曼：

It logs 你的 progress 和 it gives 你 averages 和 你 可以 see how many other 人们 are fasting. Again, totally zero cost. I actually don't know who owns 那 app, 但 I think they've done an excellent job. The interface is 确实 terrific 和 as far as I know, it's available 对于 Apple 和 Android, 但 it's at least available 对于 Apple phones, which is the type of phone I happen to have.

安德鲁·休伯曼：

So check 那些 out. My Circadian Clock, 你 just put 那 进入 Google, 你'll find it. 和 the Zero app, both excellent, zero-cost resources.

安德鲁·休伯曼：

In a moment I'd like to review the parameters of an ideal feeding schedule 对于 你 和 give 你 the variables 那 你 可以 plug 进入 你的 lifestyle 和 你的 preferences. There are a couple of things 那 I 会 place 进入 the category of frequently asked, somewhat odd, 但 still worthy of discussion.

安德鲁·休伯曼：

对于 instance, 人们 have asked, "会 brushing 你的 teeth 与 toothpaste break 你的 fast?" I think unless 你're swallowing the toothpaste, no. Now if 你 确实 want to run out 和 get a continuous glucose monitor 和 brush 你的 teeth 和 你 可以 evaluate 那, 但 no. 人们 have asked, "会 a half glass of wine 之后 dinner, a couple 小时 之后 dinner break 你的 fast?" Absolutely. It absolutely 会, 和 it's been demonstrated to do 那 based on the 一 gram of sugar kind of eerie 或 scary effect 那 I talked 关于 之前, scary 和 eerie 因为 it just seems like 一 gram of sugar, how could it do 那? 但 这些 are metabolic processes 和 they are 非常 sensitive post meal.

安德鲁·休伯曼：

A few months back I did an experiment wearing a continuous glucose monitor 和 I got a surprise when I discovered 那 going 进入 a sauna 增加 my 血液 glucose quite a bit. It actually spikes it as high as a meal 和 then it tends to drop back down to baseline 或 even slightly below baseline afterwards.

安德鲁·休伯曼：

When I talked to 人们 关于 这, somebody said, "Oh, it's got to be 那 the continuous glucose monitor was getting disrupted by the 热 in the sauna." 那's actually not the case. Turns out 那 when 你 go in a sauna, 因为 你 dehydrate, 你're losing 水, I wasn't drinking 水, 和 你're dropping a lot of 水, the concentration of sugar in 你的 血液 actually goes up. 和 I actually put 这些 数据 out in a social media post on Twitter 和 人们 were kind of shocked to see how much a sauna 可以 spike 你的 血液 glucose.

安德鲁·休伯曼：

Now, I do practice time-restricted feeding, intermittent fasting, I'm not super strict 关于 it. I use a kind of eight- to 10-小时-ish window, either early in the 天 或 late in the 天. I saw 这 effect of the sauna. Personally, the psychological 和 身体健康 effects of the sauna are valuable enough to me 那 I continue to use it. I just not concerned 关于 这 增加 in 血液 glucose to the extent 那 I'm going to eliminate sauna.

安德鲁·休伯曼：

I like to use the sauna 三 或 four times a 周 之前 sleep. So I'll use it an 小时 或 二 之前 sleep 和 yes, indeed, it creates 这 big spike in 血液 glucose 那 then drops based on change in the concentration of 血液 sugar. I'm just not going to worry 关于 it. Now if 你're concerned 关于 血液 glucose spikes, then 你 可能 be worried 关于 it.

安德鲁·休伯曼：

但 in my case, it was 一 of 那些 things where it was interesting, 和 it was worthy of discussion I thought 因为 it was somewhat surprising to me, 尽管 it makes perfect sense why 这 会 be the case, 但 at the end of the 天, literally, it just makes sense 对于 me to get in the sauna.

安德鲁·休伯曼：

So now 你've heard a lot of science, 你've heard a lot of examples, even a few anecdotes, 和 let's come up 与 the ideal intermittent fasting, aka time-restricted feeding schedule 对于 你. 和 when I say ideal, I mean what are the variables 那 are negotiable? What are the ones 那 are non-negotiable? What is ideal 对于 你 会 depend on the context of 你的 life 和 what 你 are willing to do consistently.

安德鲁·休伯曼：

So 首先 of all, 我们 established based on the discussion 与 Satchin, who is truly the premier world expert in 这 area, who knows the animal 和 human scientific literature better than anybody, has written 这 incredible review, 和 对于 whom I consulted, 那 你 do not want to ingest food 对于 at least, I want to emphasize at least, 60 分钟 post waking up.

安德鲁·休伯曼：

秒, 你 want to avoid ingesting any food of any kind, even 一 gram of sugar. Remember, 这 is the ideal, 一 gram of sugar even 会 be too much, 对于 the 二 to 三 小时 prior to bedtime. He also mentioned, ideally, 你 are spending eight 小时 in bed. I didn't tell 你 那 earlier, I saved 那 对于 now. 但 ideally, 你 are sleeping 那 entire eight 小时, 但 simply by being in bed 对于 那 eight 小时 和 avoiding food 之后 waking 对于 an 小时 和 之前 bed 对于 二 to 三 小时, 你're starting to build out the duration of 这 fasted period.

安德鲁·休伯曼：

Remember 那 the sleep-related fasting is particularly 重要 对于 the health benefits of time-restricted feeding. Again, the sleep-related fasting is 尤其是 重要 因为 of all the cellular repair processes 那 occur in the liver, in the gut, in the microbiome, in the 大脑, all over the 身体. 和 因为 of the way 那 那 coordinates the expression of the clock genes 那 are then going to wick out 和 have many other positive effects on health, including weight 和 fat loss, 但 in addition to 那, liver health, etcetera.

安德鲁·休伯曼：

An eight 小时 feeding window as a target seems to be the best target feeding window, at least by my read of the literature 和 in discussing it 与 Satchin. Shorter feeding windows of four to six 小时 tend to lead to overeating 和 potentially 增加 in weight. 一 meal per 天 type eating do not seem to do 那, 但 那些 are special cases in 那 most 人们 可以't adhere to a 一 meal per 天 type schedule, at least not on a regular basis. 和 it's not 非常 compatible 与 most social schedules, 尽管 some 人们 may be able to adhere to 那 in a straightforward way.

安德鲁·休伯曼：

但 there aren't any robust 研究 exploring the advantages of 一 meal per 天. So if 你 feel there are advantages of 一 meal per 天 对于 你 as opposed to an eight-小时 feeding window, well then by all means, use a 一 meal per 天 approach 或 use a four- to six-小时 feeding window 和 just make sure 你 don't overeat in 那 window.

安德鲁·休伯曼：

Remember 那 most 人们 tend to not adhere to the eight-小时 feeding window. They say eight 小时, 但 they tend to eat outside of the eight 小时 a little bit on each side. So if 你的 goal is a 10-小时 feeding window, 你 可能 want to set it to nine 小时 或 eight 小时. If 你的 goal is six 小时, 你 可能 want to set it to seven 或 eight 小时. 和 这 is simply based, 或 I shouldn't say simply, 这 is based on thousands if not tens of thousands of human subject 数据 points 那 Satchin 和 colleagues have collected.

安德鲁·休伯曼：

Regular placement of the eating window 或 feeding window every 24 小时 is 重要. 你 don't have to be absolutely rigid 和 neurotic 关于 这, 但 你 don't want it sliding 大约 on the weekends so 那 it's starting 二 小时 later 和 ending 二 小时 later a couple 天 a 周 因为 then 你 start to offset many of the positive health effects 那 have been demonstrated 对于 time-restricted feeding.

安德鲁·休伯曼：

Remember, if 你 eat 你的 food within a certain feeding window, 但 那 feeding window shifts by a couple 小时, it is effectively like jet lagging 你的 系统. It is effectively like traveling a couple time zones over, eating there 对于 a few 天 和 coming back, when in fact, 你're not traveling. 和 那's 因为 of the way 那 food adjusts 这些 circadian clock genes.

安德鲁·休伯曼：

Now 你 可以 offset some of 那 通过 the use of light, 和 I've talked extensively 关于 how to use light in previous podcasts, 但 again, early 早晨 和 all 天 bright light exposure as safely as 你 可以, ideally 从 sunlight, not 通过 a window, etcetera, avoiding bright light in the middle of the 夜间, extremely 重要 对于 情绪, offsetting metabolic dysfunction, etcetera. Not incidentally, Satchin's early work was he was 一 of the 三 co-discoverers of the cells in the eye, the so-called melanopsin cells 那 set the central circadian clock. So he was a pioneer in 那 field, which led him to be a pioneer in 这 field 和 so on.

安德鲁·休伯曼：

When 应该 那 eight-小时 window be placed within each 24-小时 cycle? Well, let's talk 关于 ideal. Ideal, if 你 确实 want to maximize all the health benefits of time-restricted feeding, 你 need to extend the fast 大约 sleep on both sides. 你 会 place it smack dab in the middle of the 天. It 会 be a schedule in which 你 started eating, 对于 instance at 10:00 AM 和 你 stopped eating at 6:00 PM. An absolutely dreadful schedule 对于 anyone 那 wants to have some semblance of a normal life, in my opinion. It's not 确实 compatible 与 most schedules, 尽管 some 人们 可能 be able to do it.

安德鲁·休伯曼：

Maybe 你 和 你的 family 或 你的 friends, 你're eating a late breakfast 和 then 你're having a late-ish lunch 大约 2:00 PM 和 then 你 have dinner at six. 和 then assuming 那 你 go to bed 大约 9:30 或 10:00 PM, 那 is going to extract the maximum amount of weight related, 身体 fat related, metabolic factor related aspects of time-restricted feeding.

安德鲁·休伯曼：

Some 人们 tend to fall 进入 a category where they do best placing 那 feeding window later in the 天, 和 provided it doesn't run too close to 你的 sleep. Remember, 你 need a 二- 或 三-小时 buffer 之前 你的 sleep where 你're not ingesting anything, 那's in order to extract the benefits of time-restricted feeding, well then starting 你的 feeding window at 12:00 PM 和 ending it at 8:00 PM, plus 或 minus half an 小时 或 so 天 to 天 seems like a perfectly reasonable schedule 对于 some 人们 — starting at 2:00 PM 和 ending at 10:00 PM 会 be 那 schedule.

安德鲁·休伯曼：

Of course, 你 have to take 进入 consideration when 你 运动, if 你 运动. 对于 instance, I like to 运动 early in the 天. If I run 或 if I do some moderate 或 light intensity 运动, regardless of what type of 运动 it is, I have no trouble waiting until my feeding window kicks in 大约 noon 或 even 2:00 PM. 但 if I do high intensity weight 训练, 对于 instance, early in the 天, 或 if I run sprints 和 I do 那 at 7:00 AM 或 8:00 AM, by 11:00 AM I am 非常, 非常 hungry 和 it's hard 对于 me to do other things, concentrate, etcetera.

安德鲁·休伯曼：

Now I'm not neurotic 关于 my feeding window as I mentioned 之前. I kind of let it expand 和 contract a bit 大约 the eight-小时 mark, 和 feel perfectly free to do 那 too. 我们're talking here in ideals, not in necessarily practicals, 但 other 人们 find 那 they're 非常 hungry when they wake up early in the 天. If 你're 一 of 这些 人们 或 你're somebody who 确实 is trying to emphasize hypertrophy 或 maintenance of 肌肉, then it does seem 那 ingesting protein early in the 天 is beneficial, 那 it 可以 be 更多 readily converted 进入 肌肉 组织.

安德鲁·休伯曼：

和 这 has been demonstrated in at least 一 研究. There's another 研究 underway 那's exploring 这 further. 对于 人们 那 are 确实, 确实 interested in hypertrophy 和 building 肌肉, well then time-restricted feeding is usually not the way they go. I mean, let's be honest, there are many 人们 out there who are eating four 或 更多 meals per 天 和 they're doing 那 从 7:00 AM until 8:00 PM. I realize 那 not everybody is overweight. There is an obesity crisis, indeed, the percentage of obesity 和 nonalcoholic fatty liver disease is just cosmic 通过 the roof, at least in 这 country 和 in other countries as well. 这 country meaning the US, 但 other countries as well.

安德鲁·休伯曼：

但 there are of course 人们 那 are trying to gain weight 或 who don't want to lose weight 或 who are trying to maximize 身体表现 或 hypertrophy 或 things of 那 sort. 和 so of course, time-restricted feeding 对于 them 可能 be, as long as I'm awake, I'm eating. 和 I tip my hat to 那些 人们 和 just say, provided 你 understand what 你're doing 和 the burden then 那 places on some of the other processes in 你的 身体, if 那's right 对于 你, then by all means pursue 那.

安德鲁·休伯曼：

Another thing 那 我们 可以 add to 这 summary 或 key points related to time-restricted feeding is the use of glucose disposal agents 和/或 behaviors. If 你 find 那 你've eaten too close to a period of time in which 你 会 prefer to be fasting, 那's when a 30-分钟 brisk walk 或 even modest walk 之后 eating 可以 be beneficial.

安德鲁·休伯曼：

Ingesting some lemon juice 或 lime juice 可以 help lower 血液 glucose somewhat. 和 then there are the things like metformin 和 berberine. There are even some supplements out there 那 combine things like berberine: cinnamon, which 可以 lower 血液 glucose, 和 things like chromium 和 things 那 have a mild effect on 血液 glucose. 但 berberine 和 metformin are 非常 high potency glucose disposal agents, 和 I mentioned earlier why 你 会 want to approach 那些 与 the appropriate 水平 of caution 和 figure out the dosages 对于 你. 和 then 对于 some 人们, the dosages 会 be zero milligrams is going to be ideal.

安德鲁·休伯曼：

和 then of course 我们 discussed how making sure 那 你're ingesting enough fluids, in particular 水 和 salt, 尤其是 if 你're using caffeine in order to 增加 你的 水平 of alertness, regardless of where 那 caffeine source comes 从, coffee, tea, 或 otherwise, 那 可以 cause the excretion of sodium 和 可以 lead to a kind of shakiness, a lightheadedness 和 the feelings of hunger 那 may 或 may not be related to 血液 glucose.

安德鲁·休伯曼：

Some 人们 genuinely need to eat. I certainly 会 not want to see 人们 getting hypoglycemic to the point where it's dangerous. Certainly if 你 are diabetic, 和 in fact 对于 all 人们, 你 应该 consult 与 你的 physician when exploring any major changes to diet 或 additions 或 subtractions of anything including supplementation. 但 对于 most 人们, maintaining relatively low-to-modest 血液 glucose 水平 is going to be pretty healthy 和 会 allow all the positive effects of intermittent fasting to occur.

安德鲁·休伯曼：

和 when 你 find 那 reaching 那 start to the feeding window is challenging, 那 ingesting sodium 可以 经常 stabilize 你的 系统 mentally 和 physically 和 allow 你 to reach 那 window, 经常 painlessly. 和 then as a final point, as I mentioned earlier, provided 那 they are consumed in low, no, 或 modest amounts, artificial sweeteners 或 plant-based nonsugar, noncaloric sweeteners don't seem to 确实 impact 血液 glucose to the extent 那 it 会 "take 你 out of 你的 fast."

安德鲁·休伯曼：

但 那, like fat fasting, is something 那's going to be highly individual 和 那 你're going to have to experiment 与 对于 yourself. 和 being able to recognize when 你're in a fast 和 when 你're out of a fast at a subjective 水平 和 not constantly having to measure 你的 血液 glucose 或 do things of 那 sort 可以 be beneficial. 和 I think if 你 watch 对于 the feelings associated 与 eating 和 posteating foods of 不同的 kinds in 不同的 amounts 和 你 watch 对于 the feelings associated 与 being fasted 对于 long periods of time 或 short periods of time, of having gotten sufficient sunlight, of having trained hard 或 not trained hard earlier 那 天, etcetera, 你 可以 do the most 重要 thing, which is to start to learn to evaluate 你的 own 系统, to run simple, safe experiments on 你的 系统 in a way 那 allows 你 to 确实 establish the ideal nutrition schedule 对于 你, whether it be time-restricted feeding, aka intermittent fasting, 或 some other nutritional plan.

安德鲁·休伯曼：

If 你're learning 从 和/或 enjoying 这 podcast, please subscribe to 我们的 YouTube channel, 那 确实 helps us. In addition, please feel free to leave us comments 关于 这 episode 或 我们的 other episodes. If 你 want to make suggestions 关于 future episode guests 或 episode topics, please do 那 in the comment section as well. Please also subscribe to the podcast on Apple 和 Spotify, 和 on Apple, 你 可以 leave us up to a five-star review.

安德鲁·休伯曼：

In addition, if 你're not already following Huberman Lab on Instagram, there I do brief posts 关于 science 那 经常 are not covered on the podcast. So 那's Huberman Lab on Instagram. 我们're also on Twitter, also at Huberman Lab.

安德鲁·休伯曼：

Recently 我们 launched a clips channel, Huberman Lab Clips. Please check out 我们的 clips channel 和 subscribe there 对于 brief excerpts 从 the various Huberman Lab podcasts.

安德鲁·休伯曼：

In addition, please check out 我们的 sponsors 那 我们 mentioned at the beginning of 这 episode. 那's a terrific way to support the podcast. I know 我们 covered a lot of information today. I hope 你 learned a lot 关于 time-restricted feeding. I hope 你 learned a lot 关于 代谢 和 能量 和 health 和 how when 你 eat is as 重要 as what 你 eat. 和 last 但 certainly not least, thank 你 对于 你的 interest in science.