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Science of Fasting (spyderdoc.substack.com)
221 points by sumanmd on May 4, 2022 | hide | past | favorite | 178 comments



Working from home has convinced me that a lot of western people don't really need more than one meal a day (or even one).

Growing up sort of poor-ish, I have noticed that a lot of my eating habits are basically not far off Dickensian "Eat now, you might not have anything at all tomorrow" patterns.


Animals, including us, are extraordinarily good at conserving energy and dealing with long periods of famine. One meal a day is a non event metabolically, and makes sense for most of us that lead a sedentary life.

The idea that we need to eat 3 times a day is from a time most people were living an agricultural life, or doing heavy physical jobs. If you burn a lot of energy, you don't need to be told to eat more.

The idea that we need to eat 5 small meals a day to stay healthy, and never skip a meal! is first world bullshit.


True, but especially if you are obese, find your TDEE (Total Daily Energy Expenditure) and make sure you eat close to that. You shouldn't cut more than 1000 calories a day from your needs. If you do that over a long enough time period, you can lose muscle and your metabolism will slow and become more efficient to protect yourself, making it harder to lose weight.

If you have already done this, you will have to enter into a period of building exercise and adding muscle weight back onto your body before your metabolism will work the way it should.

Sure, this is anecdotal but I was eating 1600 calories a day OMAD and my metabolism dropped to burn 1850 calories a day. (As measured by a VO2 Max machine as part of a dexafit scan), which is about 750 calories a day under what it should have been. My standing body temperature was also hovering around 97.3 instead of 98.6

Since then I've been eating more, closer to 3000 calories a day and exercising with heavy lifting 3x a week and my metabolism has come roaring back. I haven't had another VO2 Max scan but my standard morning body temp is now 98.3. In the months I've been doing that I have gained 1 pound, but I am sure a good chunk of that is muscle.


I'd rather eat 3 times a day than feeling stuffed from shoveling 2,000 kcal in my stomach once a day – and even if you sit around all day, you still burn up to 2,000 kcal.


As someone who has done one meal/window a day for a decade, I assure you it's a self-correcting problem.

You wont ever starve if your meal is 700kcal one day. You will want to eat more the next day, your head will tell you. Or maybe you want some ice cream after in the same window?

On the other point, very few people who sit around all day need 2000kcal, unless they're relatively huge in any dimension. Either way you will find out if you count for a couple of weeks and if your weight is constant your average intake is your TDEE. If you're sedentary my bet is it's less than 2k.


I kept telling people this while powerlifting. I had several years worth of detailed records of what I ate, down to every sugar free chewing gum I chewed, and while going to the gym 5 times a week combined with a sedentary job, I burned at most around 2000kcal. My bulking diet was at 2400kcal. I was at near competitive level weights at that point.

I feel so much obesity is down to people thinking 2k or even 2500kcal is right for them despite an activity level that means they might be closer to 1500kcal-1800kcal.

Absolutely concur with your advice to count for a couple of weeks, and I'd back that bet...


Can I ask your height and weight?

I'm trying to bulk now and the online calculators I'm using are telling me to take in 3,100 calories, which feels like way too much.

But I am 6'3", 195 lbs, and I'm hitting the gym 5-6 days a week, so maybe?

After years of dieting and weight loss it's hard to eat that much.


6'1, about 200lbs when at my leanest (15% or so body fat). 3100 sounds very high to me for your weight unless you're all muscle and very active, but very much in line with the kind of recommendations I'm used to seeing.

But your experience will vary massively depending on how active you are, including how hard you hit the gym.

It's not impossible it's right, but really just count for a few weeks and keep track of your weight, and then adjust up/down up to a few hundred kcal until your weight is changing the way you want it tp.

Unless you're super-lean there's very little reason to add more than 300-400 kcal above maintenance at most (I do less these days) - big bulking cycles take a lot of discipline to break out of. I generally favour slow but steady these days as I'm back into lifting.

Age also factors in - you can expect slower progress the older you get and accordingly you'll need fewer extra calories if you want to avoid adding fat. Conversely, if your testosterone levels and metabolism are at their peak, you might well burn more.

Counting and tracking is really the only thing that will tell you the right numbers for you.


Thank you for the information!


Eat more calorie dense food then. Nobody would enjoy the digestive experience of 2,000 kcal worth of broccoli (about 6.5 kg).


Not sure anyone could perform the digestive experience of 2000 kcal of broccoli in a day?


See, I like feeling full when I eat, and three meals means I never feel full - if I want to keep my calories under a healthy amount. I've compromised on two meals in a four hour window. Still lots of health benefits but a bit more manageable than one huge meal (for me).


I usually go right in the middle with 2 meals a day for the reason you mentioned.


Do you know that brain uses about 60% of the energy? If you think hard it might use more, I don’t know :)


I definitely recall feeling my head warm up after intense exams and (non-physical) competitions...

Could have been a psychological illusion, but there you go.


An old Indian saying goes like this. Healthy eating and regular fasting is a big part of ancient Indian system still followed.

Wordly people eats twice a day,

Ascetics eats once a day,

Children and invalids eats throughout the day.


I'm a normal person, which I think is morally better than being an ascetic, but I only eat once a day.


What makes you think you have to leave for jungle to be an ascetic? You are an ascetic by all means if you have control over your senses. At least Hinduism defines it that way.


Most of the ancient cultures, I do believe were fasting was a longer phenomenon, possibly days to weeks.


I've been having 1 meal a day for several years now (since well before the pandemic), and my weight has stayed pretty much constant throughout.

The tricky part for me wasn't getting enough calories, but ensuring I'm getting a good amount and a good variety of nutrients.

I try to eat healthy meals most of the time, but even a handful of "cheat" meals per week to indulge my cravings for tasty, non-healthy food can seriously throw off my overall nutrition profile for the week, since I only get 7 of them.

I've been trying to balance for that by drinking a bottle of Soylent after every unhealthy meal, basically as a nutritional supplement.


Yes we are in a culture of nonstop eating. Once we understand the basic phenomenon of fasting and or caloric restriction, its easier to restrain from eating excess.


I'd try to do OMAD (One meal a day) a couple days per week, and at first it's hard not gonna lie, but for me the reward was worth it.

The main difference its energy levels. Before it was like a roller coaster of 10/10 minutes after eating, then going low to 5 or 4 in a few hours. With fasting, it's more like a consistent 8/10 across the day.

The main challenge with OMAD, it's probably the social aspect, eating it's rarely around calorie consumption.

Bonus: Is practical only having to do clean kitchen utensils and dishes one time per day. Lot of time saved.


Unfortunately we have to overcome both instinct, motivation, and willpower.


Humans don't have instincts, except a little baby's instinct to suckle. An instinct is a pre-programmed behavior, not a desire. Only non-human animals have instincts.

Motivation is never something to overcome. Motivation is power. You work with it.

By "willpower" people usually mean ability to force yourself to do something you aren't motivated to do - you shouldn't try to do that, it's operator error of the human system.


of course humans have instincts, we're an animal like any other, just because some try to do anything they can to suppress those instincts doesn't mean it's not there


Obviously you can't give an example, since we don't have instincts.


Disgust may itself be an instinct.

Fear of spiders and snakes were found in infants.

Reflexes are instinctual.

I think we have a few instincts.


Those are not complex behaviors. An instinct is a complex behavior, like migrating for the winter or building a nest.

The problem with claiming that humans have instincts is that it gives cover for bad theories of mind. For instance, the Nazis believed Jewish people have Jewish minds and German people have German minds; many Marxists have held that bourgeoisie have bourgeois minds. In reality, the human mind is a blank slate, in terms of knowledge and beliefs.


This is exactly why obesity is a thing. We are all wired to some extent to eat whenever food is available. It's a survival thing. But food is plentiful and easily available at all times. That would be bad enough. What's worse is much of it is specifically designed to be addictive.

Sedentary people definitely don't need more than one meal a day to survive. It's trivially easy to satisfy daily calorific and nutritional requirements in a single sitting. There are still a lot of people who say breakfast is the most important meal of the day. It is if you are going out to do 4 hours of manual labour in the morning before lunch. Not so much if you only cycle a few miles to work then sit down (and that's already more exercise than most do).

However, I do think there is a difference in how people react to fasting. In particular I think fasting is better for men than for women. I've been fasting regularly for more than 10 years at this point and it's great. But all women I've known to try it have had problems with it.


I think this is true. Whenever I’m sedentary for a while I can’t eat more than two meals a day without quickly putting on weight. I don’t understand how it’s possible for people to struggle with putting on weight unless they have a very active lifestyle


It was harder to gain weight from my lowest point after doing intermittent fasting, than starting to loose from my highest point.

At the lowest point I had lost a lot of interest in food and eating and did not have the same hunger. It is much worse problem since loosing weight is only about discipline, but gaining weight is about more than that.


I work from home and from a solo office.

When I’m in the office, I crave a sandwich from the pizza place across the street A) because it’s there and B) to kill the monotony of being in my office.

At home I have a far easier time skipping lunch despite there being snacks everywhere.


> Working from home has convinced me that a lot of western people don't really need more than one meal a day

A different way to look at it would be that a lot of Western people are too sedentary for more than one meal a day. Not only are they getting fat, their muscles are atrophying from lack of activity.


I was at 24% body fat and after trying 24 hours water fast 3 times a week for 2 weeks, I have come down to 19% losing 4 kgs in the process. After this I didnt fast for 2 weeks as I wanted to confirm it was not water weight and I am still at 19%. Also, post prandial insulin came down to 18 μU/mL from 28 μU/mL (2 hour mark Kraft test). I have tried cardio and calorie reduction before to reduce fat and have got decent results but fasting is so quick so it is now going to be my preferred way for cutting.


Sorry if I'm missing the point, but of course if you don't eat you lose weight pretty fast.

I'm not a fan of CICO but when calories in = 0 and the average TDEE is around 2500 kcal, it's a pretty simple equation. The rule of thumb is 1 kg of body fat is equivalent to 7000 kcal of energy deficit.


For those who aren’t well practised in shifting their body composition ‘at will’ - i.e. nearly everyone - CICO strategy is key when they are looking to reduce body fat.

There are a few who claim, without any substantiation I can see, that CICO is not the main factor in losing fat, and I’m sure there will be some oddness around the edges which makes this at least not 100% black and white, but yes CICO itself is generally accepted as what all fat loss is driven from.

So back to CICO strategy, because it’s that which nearly everyone struggles with, not CICO in and of itself.

Choosing a strategy that is comfortable enough for a person to sustain is key to long term maintenance of desired body fat level. Some are happy to just eat at a maintenance level through three meals a day, but for many this just makes them miserable and they creep up the calories over time.

Fasting is, for many, a much easier strategy to sustain. Often there is only a small period of hunger in a short fast, but this can even disappear with practice. Fasting can feel great during the fast, and make you feel good when you’re not fasting. CICO is under your control and you’re it even finding it hard. This is why fasting is a great choice for many.


The problem with CICO is that it ignores the roles that hormones play in calorie consumption and fat burning.

By ignoring this CICO concept is not only oversimplifies what is happening in your body, but it is extremely misleading.

When you consume foods you get an insulin response. Insulin response is part of an elaborate chain of reactions that controls how your body regulates the usage of glucose and storage of fat.

Basically:

Your body will metabolize carbohydrates and fructose/sucrose sugars immediately into glucose. It will try to use this glucose as much as possible for fuel for your cells.

However too much glucose can be dangerous. So once your glucose levels in your bloodstream reach a certain level it will trigger your liver to start storing glucose in the liver.

Once the liver is near capacity then it will trigger the glucose to be turned into stored fat.

During that entire process YOU CANNOT BURN STORED FAT.

THAT is the part that CICO ignores.

One of the things that insulin does, along with associated processes and hormones, is inhibit the usage of stored fat for energy. The goal is to regulate glucose in the blood stream and store excess glucose as fat. That can't work if your body is busy consuming fat as energy.

SOo...

If you eat in a continuous manner and keep your insulin levels high then it makes it physically impossible for your body to "burn fat".

In order to lose weight using CICO you need to use up all the calories you consumed, wait long enough for the effects of insulin to wear off, and then start burning through your fat reserves.

It seems like this transition period takes times.

This is what bicyclists often see during races and such things. They load up on carbohydrates for the high energy they provide, but when glucose levels get low they "Bonk Out". That is they lose significant energy.

Where as if your glucose levels were never high to begin with then that can avoid that phenomena.

------------

One of the major problems with Americans diet is the high concentrated of sugars and complete lack of fiber.

When people consume natural fruits and vegetables high in carbs and sugars then that is mixed in with a lot of fibers. Long chain carbohydrates locked together and difficult to digest.

Which means that in order to get all the sugars out of the mass of the food it needs to be carried into intestines and broken down with the assistance of your gut biome.

Which means that high carb/high sugar foods in their natural state do not release all their calories instantly. It take several hours of digestion to extract everything.

Where as modern diets are full of extremely concentrated forms of carbs and sugars and no vegetable mass to go with it. Corn syrup drinks, concentrated juices, pasta, bread, candy, chips, etc.

These high energy foods are cheap to produce and provide a lot of "filler" in foods and are easily stored and consumed for snaking.

So as a result this style of diet produces the glucose spikes and the resulting "bonking out". Which is experienced by people as periods of acute tiredness, inability to concentrate, and lack of energy.

The easiest way to solve this is by having a quick high carb snack, which then restores the energy levels.

Which means that Americans, in order to maintain glucose levels, tend to eat 8 or 9 or 10 times a day (including snacks).

This not only promotes high calorie intake it also destroys the ability to consume stored fat as energy AND probably contributes heavily to problems like insulin insensitivity.

----------------

This is were one of the major misconceptions of fasting comes from:

During WW2 the USA observed the effects of famine among Europeans. To examine the effect of starvation diets on people the USA Military ran a number of controlled experiments involving volunteer service men.

Some of the effects observed involved intense prolonged hunger, lethargy, etc. Lots of bad effects and negative impacts to organs, various nutritional deficiencies, among other things.

It was then assumed that fasting would result in the same effects as extended starvation diets. And as been treated that way by the medical community for decades.

The trouble is that starvation diets involve regular meals, just very very limited ones. Where as fasting is no food at all.

The way the body reacts to fasting is different.

Why this is happens is theorized to be a survival technique.

Imagine you are a hunter gatherer. It takes significant physical effort to gather food.

If when you cease to eat your body sort of "hunkers down" down to conserve energy then it would potentially lead to a sort of death spiral were less and less food means less and less energy and, thus, less and less ability to get more food. You gradually become weaker and slower as time goes on.

Where what typically happens is after an extended period of not eating your hunger ceases and your energy increases. The idea being that the increase in energy allows to you work harder to hunt/harvest foods.

This is probably why it is becoming more popular for athletes to combine exercise and fasting.

-----------

And all of this, I think, heavily relates to why things like intermittent fasting, paleo diets, and keto diets are popular.

Now I don't believe that a diet of mostly steak and butter is particularly healthy, but I also don't think that a diet of cheap high-carb fiber-free "factory foods" is particularly healthy either.

I think it's likely that a high carb diet combined with moderate fats and proteins can probably be very healthy, provided those carbs come in a more "natural" format combined with significant amount of fiber.


Thank you for taking the time to explain this.


nice.


> Often there is only a small period of hunger in a short fast, but this can even disappear with practice.

I did a fast which lasted a few weeks (18days) and I could have carried on doing it for longer but I had to break it, I lost 1kg a day. Never felt so good whilst doing it, no hunger.

I think copper supplementation before fasting might help with going into a fast at will. Any nausea from copper is probably Interleukin-2 and its possible, never done chemo, but there might be copper in chemo which will explain the nausea along with the effects of Interleukin-2 which is nausea and fatigue. Copper RDA recently been lowered, controversial, from a cancer prevention perspective.

> Hence doing a workout during fasting gives the best bang for the buck.

Its why the military get recruits up and running before breakfast. The military know how to get people fit fast.

Nicotinic acid on an empty stomach will also cause a spike in a growth hormone. https://nutritionreview.org/2013/08/niacin-cholesterol-wars-...

The more fat in the diet the more the prostaglandin (the sunburn effect flush) & growth hormone response is blunted.

Niacinamide does not give you this effect, only nicotinic acid, both are classed as vitamin B3.

Nicotinic Acid in high doses can also cause abortions reportedly which might be topical for some but something to be aware of.

Also check out Herbet Shelton who was part of something called the Hygienists, he wrote a few books, but his attitude was if the fast kills you then there is nothing medicine could have done for you anyway, controversial but might be true. https://archive.org/stream/fastingcansaveyourlifebyherbertm....

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4684131/

If you get into trouble whilst at Forth Worth or Fort Bragg, they slam you in a tin shack with nothing but water and a multi vitamin to suffer the blazing heat and sweat it out. What do they know?

Supposedly, 15mins in a 80 degreeC sauna sweats more toxins than the kidneys can process in a 24hr period, so perhaps the US mil consider toxins to be the cause of bad behaviour?!?


> I did a fast which lasted a few weeks (18days) [...] I lost 1kg a day

That seems unlikely.

1kg is 7,700 calories. You'd have to burn about 5,700 calories in exercise, which would be something like a 200km bike ride completed without eating anything.

Maybe a serious athlete who had specifically trained for that could do it for one day, but I don't think anyone could do that for 18 days. For a start, I don't think they'd be fit enough to do it if they had 18kg of excess weight they could lose.


Your metabolism goes UP under fasting. Not down.

And everybody is different.

2500 is average male adult. That does not mean that he, or anybody else, actually uses 2500 calories per day.

Typically people can burn up to around 39 calories per kilogram of weight. Which means the bigger you are the more you burn.

90kg man, with an active lifestyle, would could need around 3900 calories to just maintain his body weight.

If he was a very large person who is overweight then 150 kg is not going to be very abnormal. I know plenty of guys that weigh like that don't look like fat blobs. They are just really big. Big frames, very tall, etc.

In that case then needing to consume 5500-6000 calories to maintain weight is not unreasonable. It is high, but not outside the expected range.


> Your metabolism goes UP under fasting. Not down.

Short-term fasting might. Long-term, extreme fasting slows metabolism.

> In that case then needing to consume 5500-6000 calories to maintain weight is not unreasonable.

Let's assume that's correct, and the person in question is huge and needs 6,000 calories a day to maintain weight. To lose a kilogram a day you'd still need to eat nothing and do 1,700 calories of exercise a day above baseline to lose a kilogram a day.

You probably wouldn't be able to eat nothing for 18 days, so you'd actually have to burn the equivalent in exercise for whatever you ate.

Let's play with some numbers. Some of the heaviest athletes around are front-row rugby players. 150kg would be right around the top end of that range. If they were on a 50% calorie reduction diet they'd be needing to burn 4,700 calories a day. That's still about 100km of cycling even if you're 150kg. On a very restricted diet. For 18 days in a row.

I believe some Buddhist monks go in for multi-week extreme fasts, but I think they spend their time meditating rather than doing exercise.


All this talk about exercise and not one of you mentions my brain!


Too late to edit...

CICO is under your control and you’re it even finding it hard

->

CICO is under your control and you’re NOT even finding it hard


Losing weight is not about CICO. Of course you need more calories out than in. Saying that is like saying “To climb a mointain, make sure every day you ascend more meters than you descend”. How useful is that piece of wisdom? The rule of thumb is that for each 1 kilometer of additional elevation, you need to ascend 1000 more meters than you descend.


huh? I think you contradicted yourself. Losing weight absolutely is about CICO. You can't consistently eat more calories than you burn and lose weight.


I’m saying CICO is a truism. Telling someone losing weight is about CICO is as valuable as telling someone that mountain climbing is about taking more steps up than down.

Imagine someone sharing their experience with some new climbing gear, and someone else chiming in “All this gear talk is irrelevant, just make sure you take more steps up than down”. What value does such a comment bring?

The OP was sharing with us his experience with fasting. The response was pretty much “your fasting was not relevant. Just the fact that you burned more calories than you consumed.”


What? Your first two sentences contradict each-other and then your analogy makes no sense


CICO = Calories In Calories Out

F*ck acronyms, BTW


I'm sorry. I am founding member of the Fuck Acronyms club, and I thought this one was commonplace enough not to need an explanation. I stand corrected.


FAC represent!


Slight tangent:

Remember to breathe properly and/or deeper, or incorporate breathing exercises/meditation as part of (water) fasting. The majority of the metabolized fats gets exhaled via your mouth (and tiny amount in sweats/urine) - you do not poop it out. Breathing is very important and often ignored in weight loss. Obviously if you exercise you automatically breathe more, but you might still be taking in swallow breaths. Become aware of your inhale/exhale cycles and focus on releasing the extra store energy on each exhale.


Is a 24 hour fast the same as one specific meal a day? Like you have breakfasts on the days you're fasting?


Generally would be taken to mean you had a meal at night then go to sleep. then the following day eat nothing and go to sleep. Eat normally when you wake.

Eating one meal a day even breakfast would be considered a 23-1 intermittent fasting schedule or something, but realistically you are in a fed postprandial state for several hours after the meal so there's some daylight between one meal a day and actual 24 hour fasts.


I'm currently doing an eating window of about 2-3 hours, but I don't really track it. However, to maintain my weight, I've been doing 1-2 days of very low calories, similar to the PSMF diet from back in the day. In practice, I just eat 1.8g/kg bodyweight of protein and still take my daily supplements.

I find not eating throughout the day helps me to maintain stable energy levels and focus. Also, on even on the vlc days I'm not any hungrier because I had a full meal the day before. No hunger pains or cravings at all.

One of the strangest sensations is still pooping 2-3x the next day even though I haven't eaten anything. You quickly realize that all the food you ate takes longer to fully process than you thought.

I usually eat after work and going to the gym. In order to make sure I can still exercise; I just make sure to have some electrolytes in the water I take to my gym and I'm usually fine. Sometimes it gets sketchy on intense days, but if I know it's going to be a hard day in the gym, all I need is about 30-50g of carbs and I'm fine.

My diet still isn't very good. Typical American diet. However, I find it easy to eat high octane foods that used to put me on my ass literally or mentally if I've been "fasting".

Fasting is my favorite way to maintain and lose weight. It's very braindead, time efficient, and cheap once you get used to it. After you become more aware of your bodies hunger sensations and all the habits you have wrapped around food, the biggest thing with "fasting" is making sure you get enough electrolytes.

I've done a few pure water fasts up to a week in duration and a few 2-3 day dry fasts with one four day one. Pure water fasting I tend to be fine for about 4 days and then my energy/focus will start to drop. Dry fasting it happens in about two days.

Technically it's not fasting with the electrolytes. But for weight loss, it doesn't really make a difference.

It's interesting watching science tease out the benefits of very low calories versus very low calories and a restricted eating window. In a weight loss context, I don't think it matters that much really in terms of additional weight loss.


Super interesting - you are describing my experience with fasting to a tee, it’s almost eerie.

I also have a eating window of about 2 hours. It’s super easy to follow on since I never eat breakfast and most days I skip lunch too. The only time I eat lunch of theres a social reason, e.g going out to eat with a college or friend and I don’t want to weird them out by not eating.

I’ve done multiple 2 day water-fasts and my longest fast was 5 days. What you mention about electrolytes is 100% my experience as well, you need to make sure you get enough salt even if that means just drinking plain salt water. Not supplementing 5-10g of salt really makes me feel like shit very quickly during a water fast.

> After you become more aware of your bodies hunger sensations and all the habits you have wrapped around food, the biggest thing with "fasting" is making sure you get enough electrolytes.

This is the big thing that many people don’t understand about how you function when you’re fasting. They think its like a Low Calorie Diet where you end up hungry and low energy all the time, but its strictly the opposite from my experience. Whats super interesting in my mind is this awereness that you also describe of understanding your body more. I can tell if I am hungry just because of the hunger hormone (which has basically no relation to if you actually need food), and if I am actually starving and need to eat because my body is lacking nutrients. It’s subtle but you can actually train yourself to notice this.


Have you noticed any significant mood changes as a result of fasting? Unexpected bursts of anger, impatience, being "too straightforward" with your peers or spouse etc? This is something I've experienced while on intermittent fasting.


These sound like withdrawal symptoms. It takes time for your body to adjust to a new regime, and for your mind to learn to ignore your bodily withdrawal screams.

I regularly fast (one day every two weeks), and the greatest benefit to me is a more mindful awareness of my gut: I can now tell the difference between feeling hungry because my body expects food and feeling hungry because my body needs it, and can easily decide to delay or skip a meal if I don't really need it. And, more importantly to me, I never feel the need to snack in-between meals.


Do you know if you lost more fat with a dry fast than an equivalent water fast?

I have a theory the body will sacrifice extra fat for its water content.


The converse appears to be true (lipolysis increases with hydration).

https://pubmed.ncbi.nlm.nih.gov/14681716/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4901052/

Breakdown products of fat are something like 16% water, but you also need enough water for hydrolysis of triglycerides to get lipolysis going.


What is/was your motivation for two, three and even four day dry fasts?


Great. Fasting is easy way to be in shape and also build muscle.


Fasting isn’t going to get you “in shape”, you need some sort of exercise for that.


Peter Attia who has done extensive self-experimentation with fasting for health and uses it in his medical practice noted that without strength training during fasts his body fat really increased.

https://www.menshealth.com/fitness/a37508857/intermittent-fa...


I'm a Christian. One of the key points of fasting is to humble yourself; it is a way of saying "food is less important than my relationship with God".


Question on caloric restriction. I have read that it is the main reason that fasting (even intermittent) works. I heard mice that ate 40% fewer calories lived way longer or something like that.

I'm a thin dude (6'3" and 165lbs). If I don't force myself to eat I will drop towards 155lbs, as has happened before. I eat in a 6-8 hour window daily but I aim for 2000-2500 calories. What would caloric restriction in this context look like?


I'm not sure why you would want to restrict calories in your case? Even if the work on fasting from animal models carries over to humans beyond the benefits of reducing metabolic syndrome (which is unclear), being underweight is definitely a risk factor for all cause mortality.

If anything it kinda sounds like your natural 'set point' already has you calorie restricted insofar as it would.be beneficial


Well, at this height, are you not calorie-restricted already?


Depends on the activity level. According to this calculator:

https://www.calculator.net/bmr-calculator.html

his (assuming a dude) energy expenditure is:

Basal metabolic rate: 1819 cal/day

Sedentary (little or no exercise) 2,183

Exercise 1-3 times/week 2,501


If he is in the "little or no exercise" category, he should aim to get into "Exercise" category. Exercise (in reasonable amount) is healthy whether you loose weight or not.

He should not be aiming for "basal metabolic rate".


So does caloric restriction in general just mean maintaining a low-ish BMI?


For an animal model I imagine it means being fed less than would have been eaten ad libidum, or less than was eaten by a pair fed individual.

But considering you are probably in like the <= 3rd percentile of healthy humans in terms of BMI, your 'normal' calories are pretty damn low and probably commensurate with what would be considered calorie restricted.


So if I'm eating more and gaining lean muscle, I could still fall under the calorie-restricted category?

Basically I don't enjoy being thin but I do want to live to 120. I already do calisthenics and basketball regularly, just wondering what else I could do to min-max my longevity.


I don't think mechanism is worked out well enough to say for sure that being calorie restricted for someone like you that already is lean and not at risk of obesity related disease would be beneficial.

My first guess would be that even if there are longevity benefits for calorie restriction, depending what the mechanism is, you could either be already enjoying them by virtue of clearly not eating that much relative to your lifestyle and metabolism, or alternatively that any benefits of starving yourself enough to clamp down on mToR or some other hypothesised mechanism may well be counterproductive by pushing you close to malnutrition or just increasing your risk of injury or whatever.

I guess you could do a self experiment if you were really interested, try a fasting mimicking diet regimen where its five days a month every month to get the benefits of calorie restriction, and see if you can maintain lean mass while getting improvement in markers.


> just wondering what else I could do to min-max my longevity

Stay indoors, don't engage in medium to high risk activity, invest all your money into aging research.


Don’t drink alcohol and stay out of cars.


I think you should think about it as consuming less energy than your body needs everyday.

This specific commenter could be considered too light for his frame. 165lbs is only 75kg. If anything, eat more and put on muscle.


drop 800 calories and watch your weight for a month, you should be able to get a pretty good idea how much.


Black coffee and water from 5 am to 6 pm, eat from 6-9 pm works for me.

Meals definitely taste better after that window :)

I find I sometimes have like two dinners at 6 and 8 which is interesting…


I did this for two years, lost a fair bit of weight. But the gorging at dinner time really messed up my cholesterol levels. So just an advice that one's weight isn't the only metric of health, if you do any diet change consult your doctor, and confirm health across multiple dimensions (blood tests etc).

Today, I do a heart healthy diet, and try to fast from 8PM-12PM (eat between 12PM-8PM). This helps me not eat/snack unhealthily in a condensed period of time.


Wasn’t the link between high cholesterol and heart disease debunked in recent years? I had the impression that it was the excess carbs / sugars which are what causes health problems.

And high cholesterol in and off itself is not problematic, if your other stats are in line. E.g. high cholesterol can be a pointer to other problems, but it itself is not considered dangerous.


> Wasn’t the link between high cholesterol and heart disease debunked in recent years? I had the impression that it was the excess carbs / sugars which are what causes health problems.

So did a lot of other people, some of whom were in good shape went on keto, and needed a bypass after not too long.

Total cholesterol isn't necessarily that predictive but non-LDL cholesterol/APOB are strong predictors of CVD


Curious, what was it about gorging at dinner time that messed up your cholesterol levels? Was it because you'd gorge on foods high in cholesterol, or was there another mechanism at play?


I probably implied more causation than I meant. I know nothing about fasting causing my high cholesterol directly. What I do know is I thought my weight not going up liberated me into eating whatever my heart desired in my 4-5 hour feeding window. This feast/famine mentality did me no good given my personality type and I probably ended up eating a lot more food and snacks than I would of otherwise.


My doctor gave me A cursory explanation so I can’t vouch for my limited understanding.

That said, cholesterol is essential for the production of bile which breaks down foods. Late night foods probably equates to excess cholesterol released to break down said foods and higher cholesterol levels.

We probably want to have periods of fasting in order to not produce excess cholesterol.


There are multiple mechanisms as play when we discuss about cholesterol. I will do an article discussing about this in the future.


> cholesterol is essential for the production of bile which breaks down foods

So maybe the person fasting had higher cholesterol levels due to his body needing more bile immediately to breakdown a larger amount of food at once? I am very much not a doctor or at all educated in these topics.


Great. Congratulations on you IF journey.


Worth it to point out that coffee (and anything you ingest really, including water) will activate bits of your metabolism and having it will not be equivalent to a complete fast for certain purposes.

Not that you're wrong having it, just something to realize. Will almost certainly have a negligible or even positive effect on weight loss.


Generally (and certainly most of the recent fasting trends) fasting is referred to as no more than 500 kcal intake, which is of course different to a ‘true’ definition which would be nothing, except maybe water


500 Calories!? That’s so much.

1 large boiled egg is 80 Calories. So like eat 5 or 6 eggs and you haven’t broken your fast??


500 calories is my breakfast most days. that's not a fast!


500 cal doesn't constitute for water only fasts.


Fasting definition keeps changing. There is water only and then there is water only and less than 500 Cal.


I guess that depends. 500 calories is 1/3 of my wife’s maintenance calories.


totally agree!


Just as a word of warning, acidic coffee and late night eating are two habits heavily associated with acid reflux/GERD.

I had similar habits, was relatively healthy, and rarely if ever suffered from heart burn. But about a year ago, seemingly overnight, I came down with severe acid reflux. I am still managing symptoms to this day.

Not saying it will happen to you, but just raising awareness that human health is a fickle thing and it can take a turn for the worse quickly, often with little to no warning.


Good point, I do eat a lot of yogurt and salad and stay away from super greasy foods to prevent reflux :)


I’ve found eating once a day to be quite tough on the finances. We often eat out, so instead of ordering just dinner, I get all my calories from that one meal, which ends up being quite expensive. So at least for me fasting turned out more expensive :-D

On the plus side, I like to try different dishes, as I’m a very curious eater, and now I don’t have to feel guilty when I do.


You should pregame with a pint of greek yogurt!


Am on same one meal a day scheme (espressos in morning, nothing but dinner) for a year and love it. However, it's literally just replacing 2/3 meals out of my day with multiple servings of a highly addictive stimulant. Obviously I'm fine, but I am sure our descendents will look back on coffee as some kind of traditional folk-meth.


Great!


Very interesting, do you know the total calories you generally eat during that window?


Less than 500 - 800 cal and no carbs for 2 days.


Do you not burn up your stomach from the acidity of that diet?


Do you mean because of the coffee? I drink several cups of strong black coffee on an empty stomach every day and I've never had any problems whatsoever.


I know a couple people who had issues with the acidity of coffee generally, who switched to Liberica beans (from the more common Arabica) and no longer have any issue. I personally prefer Liberica in general. The lower acidity comes with a smoother taste that some people like.


Liberica seems hard to buy. And by that I mean I couldn't find any decent options on Amazon. Anyone know how to buy whole beans in the US?


Len’s Coffee![0] They ship all over the US. Based in Medford, MA.

[0] https://lenscoffee.com/


Thanks, but seems like they're all out of stock too?

https://lenscoffee.com/coffee-by-type/liberica/


this is great info for me; thank you


That's awesome, and, yes, that's what i wondered; personally i couldn't, presumably different from person to person.

Thanks.


It varies a ton per person - I know that I often, for example, end up with the opposite of acid reflux (essentially my stomach is too basic). I would have similar symptoms and take an antacid and it would make it immediately WORSE.

Not sure if this is why but I am also one of those people that can eat super acidic foods all day no problem - I can drink black coffee and follow that up with a bunch of citrus and feel great.


Looking it up, citrus is alkaline-forming, not acid-forming, and things that are acidic in their initial form don't necessarily increase system acidity; they may have an alkalizing net impact. Apparently your body's response to food is the important bit.


Interesting - in the past I had read about alkaline vs acid "forming" but assumed it was sort of pseudoscience BS (maybe mainly due to people recommending expensive "alkaline" water). Not sure if Tomatoes are in the same boat as Citrus but I have dated people who could not even think about drinking coffee and tomato in the same day - acid reflux disaster.


oh wow, i'm the opposite: non diluted coffee and i burn, even got scoped and showed gastritis...i evidently am at the acidic end, or just not healed enough, in a vicious burn cycle perhaps...


The HN news hoardes will probably be here soon to chastise me for even remotely giving health advice over the internet but when I had an ulcer I found out that in Japan doctors will actually prescribe powdered Glutamine (its just an amino acid - common building block of protein - so pretty damn safe) for ulcers and many things that involve the lining of the GI tract. Apparently the walls can directly use glutamine to help repair themselves. Seems to help me a lot and I just regularly started taking small amounts of it daily since I sometimes love eating an exorbitant amount of spicy food and that can be pretty harsh on your insides.


super useful info for me to at least look up. thank you!


yes it varies from person to person.


thanks


Interesting, whatever works !


Worth being aware of the UCSF trial [1] that did not find that intermittent fasting (16 hour fast / 8 hours to eat) reduced weight. A bit concerningly, they did find that there was significantly reduced lean mass in the intermittent fasting group compared to the control group (a small but statistically significant effect).

1 = https://jamanetwork.com/journals/jamainternalmedicine/fullar...


I recall reading that this is true, but the narrow eating window is believed to contribute to ease of adherence. (No citations on hand, sorry.) My dieting successes have come from both a narrow eating window and lower carb (basically less sweet fruits, and non-root vegetables).

Last time I adhered for 40 or so days I hit the wall hard (approx. -10 kg). Zero energy, and miserable. I wasn't sure if it was electrolytes or if I finally found the keto flu (seems a bit late though, and didn't pass in 3 days). So I abandoned ship and have since had no trouble putting 5 kg of fat back on my body. Time to restart!


This study by its own admission has no access to information on the amount of energy consumed by either group. It is possible to eat as many calories in one sitting as it is across the day; therefore, it is possible that people ate about the same calories/perhaps regulated by homeostasis.


> therefore, it is possible that people ate about the same calories/perhaps regulated by homeostasis.

Are you testing for the effects of fasting or calorie consumption?


Adding a data point:

Recent article on the New York Times about this study:

https://www.nejm.org/doi/full/10.1056/NEJMoa2114833

https://www.nytimes.com/2022/04/20/health/time-restricted-di...

The study refers only to restriction in search of weight loss.

Edited to remove one word that may have been perceived as sarcastic.


When I fasted I ended up gaining weight after a while. My assumption is that my body knew I wouldn’t eat for a while so it would absorb the food and not digest it as effectively so that I can have more fuel.

What I do now is I randomly fast on random days and random times . It’s been more effective for me


yes, fasting is unique to everyone. we have to understand our bodies and do the trial and error.


Meh, once again with this fasting fad. There's no evidence at this point that fasting is superior to continuous caloric restriction. There's also no evidence that any of the touted health benefits of intermittent-fasting are special to this method of weight loss -- any of them can be achieved by a regular caloric restriction diets. Most of the health benefits are due to weight loss / fat loss.

Longer fasts (over 16 hours, IIRC) are also catabolic to muscle mass, so they're not even recommended for people who have optimal training plans.

One meal per day is also not enough as only a certain amount of the consumed protein is going to be used for muscle protein synthesis so it's optimal to spread the consumption across multiple meals.

If you lift (and you should!), you should strive for 1.4-1.8g/kg of protein per day, try to hit the leucine threshold per meal (even though this is just a hypothesis!), and use calorie cycling to consume more of the protein around the workout window (anabolic window -- it's not been debunked!!!). Try not to go below 50g fat per day, and do whatever you please as far as carbs go :). I'm personally not a fan of keto as it's too restrictive.


I highly recommend this episode of the Huberman Lab podcast about intermittent fasting from a Stanford professor: https://youtu.be/9tRohh0gErM


Thank you will check it out.


I've been long exposed to the standard tech-circles common knowledge about intermittent fasting (IF), the benefits of fasting, basic gym science about calorie restriction, and so on. I thought a lot of this stuff was pretty well confirmed by science as well as various fasting-oriented traditions around the world. Fast one day a week, live longer. Work IF into your eating schedule, increase your productivity and give your body time to 'clean up' your system.

But I was surprised to recently realize how novel a lot of fasting research is, and how unconfirmed a lot of the benefits are. Even the wikipedia page for fasting doesn't have as much as I'd really like to see. It's nice to see posts like this one, but even this doubles down on "there are studies in progress" without any convincing completed studies.

Review studies such as this[0] one basically confirm in so many words that "additional trials are needed" and while IF can help you lose weight "whether IF itself affects cancer-related metabolic and molecular pathways remains unanswered"

It's curiously similar to woo-woo or religious habits and self-help advice: similar in being fringe from the perspective of scientific medicine. But the same groups who I'd expect to be pro-science (for example more likely to get vaccinated) are often mixed up in fasting stuff which isn't (yet) confirmed.

I suppose it's not too unheard of to see tech circles overlap with fringe medicine. Check out r/nootropics for instance. Now, I've experimented with nootropics and various supplements. I don't use the term 'fringe' as a haughty outsider. I'm quite willing to consider that it's "not yet confirmed" protoscience, and that this is different from falsified or counter-indicated "remedies" and bits of fringe medicine, things like homeopathy. But it's curious nonetheless.

[0] https://acsjournals.onlinelibrary.wiley.com/doi/10.3322/caac...


It's really only curious if you consider individuals themselves to be "within science" or "pro-science" as some meaningful identity- or category-like distinction. Which, ironically, does feel a bit religion-like. Like participating in an untested or disproved practice is doing a heresy or something.

Anyway people aren't science we are just people. Everyone has some beliefs and activities that they find valuable for themselves in ways that science can't measure or verify. It's fine.

I realize this could come across as pretty negative or hostile and I really don't intend it that way. I think if anything the problem is that we've sort of constructed a framework where practices are valid only if they are scientifically validated, which incentivizes people to use the jargon of scientific validity to justify practices they find valuable.

Something I find consistently funny about fasting particularly that you kind of pointed out: just because it's new to science doesn't mean it's new to us. I fast for religious reasons, my religion has a fasting tradition going back thousands of years. Its personal spiritual benefits are attested by many over much time and I find it so as well. Good enough for me. The fact that tech nerds just got hyped on it and provoked a bunch of studies in the last decades is fun, but literally a few billion people globally fast for non-scientific non-productivity reasons and will continue to either way.


I agree with everything you've said here.

I do wish science could catch up to some of these old-and-probably-quite-true traditions.


I think a large part of the problem is we may never have big studies for this. It’s very difficult to do human trials, you can’t just lock people up and restrict their calories for years on end.


the bigger question is: who would pay for such studies?

big pharma? government lobbied by big pharma? universities given grants from government lobbied by big pharma?

actually though, the soviets did do serious research into the science/benefits of fasting. Too bad it never really made it to the west.

Watch the video: "The Science of Fasting" for an overview.


There are many studies in the animal models and limited data in humans. It is hard to do studies, but NIH has a grant and many trials IF and Cancer therapeutics.


I've been fasting for 25 years. It's called being poor.


What’s so particularly frustrating is that despite record unchecked obesity, we are encouraging children to eat more than ever. In infancy, we always have bottle or breast ready where they cry. In toddlerhood, most activities and all preschools include “snack times”. My kids elementary school has 2 snacks plus lunch plus a snack for after school. Then if sports they are encouraged to have a snack before or after. Add in breakfast and dinner and they are eating 7-9 times a day! Additionally, the vast majority of these “snacks” require they be non-perishable which usually means mostly carbs and fat. I don’t understand why there is this constant emphasis on eating when it seems clear we eat entirely way too much.


My detailed write up on fasting/caloric restriction and necessary adjustments we need to emphasize in our current daily dietary regimen and this possibly helps keep the metabolic and other diseases at bay, especially in at risk populations(south Asian).


How about the combined effect of intermittent fasting and exercise regimes? One thing I've heard is that fasting lowers metabolism, so perhaps one meal in the morning followed by endurance exercise later in the day would counteract that tendency.


Sounds really unpleasant honestly. I pretty frequently eat only one insufficient meal/day or fully fast for non-health reasons and there's no getting around the fact that exercise on those days fucking sucks.

If there's any benefit I can't see it being worth it except in extreme cases. Particularly endurance exercise without calories afterwards is one of the worst things you can do to your day.


Science actually suggests fasting increases metabolism, or at least keeps it stable, unlike general caloric restriction.


Generally if you're training it's helpful to train fasted, the idea being that you want your body to adapt to consuming fat for energy rather than relying on other fuel sources.


My experience after a few years of OMAD fasting is that my body adapted really deeply. I don't get hungry (as long as I do eventually eat) and I have consistent energy levels throughout the day. If I know I'm about to do some long hike the next day (sometimes very long! 30+ miles) I try to eat extra the day before so I won't run out of energy the next day, which has also happened to me towards the end of a hike.


Fasting brings quick results. Many on this site have trouble making sustained life changes because they spend a lot of time on the internet, and excessive internet use fuels impulsive habits. This leads people to choose health interventions that bring quick results that they can use to conclude a novel, controversial stance. When faced with RCTs, or waiting a decade to report an anecdote, or generation-long observational studies, or comparing with other more normal interventions, it's understandable why the broscience is attractive. We need positive results now.


While it does get you the fastest results if your goal is to gain wait, I personally wouldn’t put fasting into the same “impulsive” bucket.

If anything it should be the other way around - fasting can be a way to teach yourself to tolerate/control your impulses.

Anecdotally - the more I practice some form of it the more benefits I seem to derive.

Just last month I noticed people dosing off in a long, tedious late afternoon meeting. For me though it just felt boring, but I could easily concentrate and stay focused. Since my only meal for the day is dinner, I’ve forced my body to generate glucose continuously throughout the day, so my brain has enough fuel, and I don’t need to rely on snack and chocolates. No sugar - no insulin spike - no afternoon sleepiness.

I’ve stopped yo-yoing with my wait, as I’m pretty inconsistent with my exercise. It’s a lot simpler for me to force myself not to do something (eat) than to force myself to do something (train).

Not to mention the whole longevity thing that is getting the rounds in the scientific community in recent years.


Fasting brings quick results but also long lasting.


Few years back my doctor was concerned about my blood pressure and recommended I lose weight. I asked how and he after the expected recommendations about eating healthier and exercising he added, "but whatever you do, don't fast." I asked why and he said it doesn't really work better long-term but increases the risk of other health problems especially gall-stones. A year later I weighed 10% less and my blood pressure was normal again. I ate less salt, fat, and sugar plus took-up soccer again. Years later I'm still not chonky again.


Are you saying you did fast or did not fast?


I didn't fast, I consumed less fat sugar and salt and played soccer but ate at the normal times.


Very interesting. I alway thought the key of longevity is speaking Japanese.


Weird, I thought the key to speaking Japanese was longevity.


After eating only dinner for years, a month ago I found myself eating every other day (except for two pieces of fruit in the afternoon) and I feel even better since then? Where is the limit?


This sounds at least to me an awful lot like disordered eating. If it works for your, fine, but anyone else reading this should take caution and consult a physician before attempting anything like this. I'm worried that some of the tech trends around intermittent fasting are starting to sound like dieting advice form teen magazines in the late 90s and early 00s.


From the environment in which early humans evolved, it is far more disordered to eat 3 square meals a day.


I'm not arguing that 3 meals is the best pattern of eating, I'm saying that advocating for and glamorizing someone only eating every other day looks a lot like the way anorexia presents among dieting influencers today and teen magazines of 20 years ago. It's clear where that path leads, and I'm urging caution.

This is also just an evolutionary form of the appeal to antiquity fallacy. I might also point out that we have no clue how early humans apportioned meals throughout the day.


Except I am not advocating or glamorizing anything. I have no idea where you think "that path leads" or why you are equating having dinner every other day with having a disorder, anorexia of all things.


Like I said, you should do what you think is right for you but I'm cautioning other people that only eating every other day is a classic sign of an eating disorder. Again, you may well be fine and getting enough calories I'm not judging you at all. Classically things like skipping meals and fasting aren't determinative of disordered eating by themselves, no one would say that fasting for religious purposes is a disorder but this kind of behavior in the right context can very quickly tip in a bad direction.

I'm again not trying to say anything about YOU, only cautioning other folks here that the intermittent fasting trend among tech folks looks a lot like social trends among other populations that turned out to be very unhealthy and that people should be cautious.


> Where is the limit?

You lose roughly ~0.75 lbs of body fat at normal fasting levels assuming a reasonably active regular sized person. So how ever many days worth of body fat you would like to gain and lose regularly. You would have to eat back the same amount and probably wouldn't want to gorge yourself too much. A reasonable practical limit might be 5 days.

All of that assumes that you want to maintain a set weight. So the real limit is how much you want to eat in a single sitting. Take those calories and average them across as many days as needed to maintain weight.


Can you explain the .75lbs number you provided? How often do you anticipate a person to lose that much? Care to provide literature for your claims?


Not the GP, but a pound of fat = 3500 kCal. If you use the standard 2000 kCal / day basis, that gets you to .57 lbs fat loss per day.

Also, the 450 pound (204 kg) man who did not eat for an entire year [0] lost 0.72 pounds / day.

[0] https://pmj.bmj.com/content/49/569/203


That person seemingly turned his health around from 456 lbs to 180 lbs. But he died at age 50. I am scared of fasting because I dont think there are enough studies on humans to understand the long term effects like gallstones and lean tissue loss, especially heart muscle.

[0] https://en.wikipedia.org/wiki/Angus_Barbieri%27s_fast


He represents such an extreme case, it is hard for me to draw any broad conclusions from his life. The man never had a healthy relationship with food.


1lb of body fat is ~3500 calories. An average person doing average things burns around 2000 calories. You can easily put in your own numbers and get your own results. Just calculate your TDEE(total daily energy expenditure) and look up how many calories in a pound of fat to whatever tolerance you want.


Most religions have some component of fasting, like Ramadan or Lent. Certainly there's value in doing more with less


Those are for purely religious reasons though and have nothing to do with health concerns, so I'm not sure what you're getting at?


While wary of noise levels (eg rules established to abuse power within the hierarchy), it's not unreasonable to assume some religious rules developed empirically over time. Not eating shellfish likely due to risks of disease, for example.


Fasting can work well for weight loss but it must be done with care.

https://www.youtube.com/watch?v=tWlvWYGztYk

Dr Bernard has some to say on this matter, after his case of the woman who experienced refeeding syndrome and had to be hospitalized.


Why aren't there any large-scale studies on this? It seems that even with all the meal tracking apps out there now, we would have an amazing data set on fasting.

It's crazy that the best we have are either animal studies or some UCSF study of ~100 people for just 12 weeks. (Very low-power study)


everyone is looking for a fix to weight gain, not even a quick fix, and various ideas and diets keep have been floated, much with limited to no success. There is no science behind fasting .If there were a science it would be effective and reproducible.


Since lockdown I have been consistently eating 1 meal a day, with occasional 2 day fasts and rarely 3-4 day fasts. It is so natural to me now that on my last stay in London I got 2 days in to the trip when I suddenly realised I'm in London, surrounded by amazing food I can't get at home, I should eat more and enjoy. So I gorged on Indian, Jamaican, Vietnamese, I was surprised how much I could put away, so much walking had stimulated my appetite.

On the science of fasting. It was Ancel Keys whose research, in the 60s, led to the invention of the Mediterranean diet as a way of reducing obesity and heart disease in America. Keys work provided the intellectual justification for the McGovern senate committee, in 1977, to propose radical changes to diet and to government policy. The top-down approach to the national diet led the government to adopt the Low Fat Diet as policy, e.g. the https://en.m.wikipedia.org/wiki/National_School_Lunch_Act

Can you spot 1977 on this obesity chart? https://www.ncbi.nlm.nih.gov/books/NBK19623/figure/chartbook...

Since Keys death, dissenting voices have gotten louder: "In the December 2004 issue of your journal, in his column, Geoffrey Cannon referred to Ancel Keys’ Seven Countries Study and the fact that Keys and his colleagues seemed to have ignored the possibility that Greek Orthodox Christian fasting practices could have influenced the dietary habits of male Cretans in the 1960s. For this reason, we had a personal communication with Professor Christos Aravanis, who was responsible for carrying out and following up the Seven Countries Study in Greece. Professor Aravanis confirmed that, in the 1960s, 60% of the study participants were fasting during the 40 days of Lent, and strictly followed all fasting periods of the church according to the Greek Orthodox Church dietary doctrines. These mainly prescribe the periodic abstention from meat, fish, dairy products, eggs and cheese, as well as abstention from olive oil consumption on certain Wednesdays and Fridays. However, it is indeed the case that this was not noted in the study, and no attempt was made to differentiate between fasters and non-fasters. In our view this was a markable and troublesome omission. The Greek Orthodox Church prescribes almost 180 days of fasting per year. It is unknown to what extent the Cretans who were the original subjects of the Seven Countries Study and who fasted during Lent also followed the precepts of their Church throughout the year, and thus on how many days in total and to what extent the Cretan participants of the Seven Countries Study fasted" https://www.researchgate.net/publication/7530689_The_Seven_C...

The fatal blow to Keys' lipid hypothesis was dealt in 2016 after data from another Keys' experiment was re-examined. "Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment" concludes:

Results – The intervention group had significant reduction in serum cholesterol compared with controls (mean change from baseline −13.8% v −1.0%; P<0.001). Kaplan Meier graphs showed no mortality benefit for the intervention group in the full randomized cohort or for any prespecified subgroup. There was a 22% higher risk of death for each 30 mg/dL (0.78 mmol/L) reduction in serum cholesterol in covariate adjusted Cox regression models (hazard ratio 1.22, 95% confidence interval 1.14 to 1.32; P<0.001). There was no evidence of benefit in the intervention group for coronary atherosclerosis or myocardial infarcts. Systematic review identified five randomized controlled trials for inclusion (n=10 808). In meta-analyses, these cholesterol lowering interventions showed no evidence of benefit on mortality from coronary heart disease (1.13, 0.83 to 1.54) or all cause mortality (1.07, 0.90 to 1.27). Conclusions – Available evidence from randomized controlled trials shows that replacement of saturated fat in the diet with linoleic acid effectively lowers serum cholesterol but does not support the hypothesis that this translates to a lower risk of death from coronary heart disease or all causes. Findings from the Minnesota Coronary Experiment add to growing evidence that incomplete publication has contributed to overestimation of the benefits of replacing saturated fat with vegetable oils rich in linoleic acid." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4836695/


Fascinating. Do you mean the mediterranean diet entirely misses the point that what drove health benefits was fasting instead of specific dietary inputs?

I can't imagine this was lost in translation.


That's is the suggestion from the scientists that re-examined it. In fact, there where many scientists that never believed it at the time, and wanted further research, but McGovern famously stated that the government did not have the luxury of time to wait for science.

Any similar nutrition model needs to account for the fact that France, Japan and Korea and have the highest intake of saturated fat, and the longest life expectancy in the world.


Great. Thank you for your awesome comments.


most of us will do less than 3 meals in the next 60y

possibly less than 14 per week but not for health related reasons


[dead]


Awesome. It does have lot of benefits especially reversing the metabolic disease.




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