There is a lot of evidence beginning to emerge on the value of fasting. This was once encoded in culture as almost every culture had some concept of fasting. We lost so much knowledge when we let nutrition "science"[1] completely overwhelm the wisdom of our ancestors.
On a personal note, I found fasting became much easier after I changed my diet to be ketogenic. With a metabolism primed for burning fat for energy and not subject to a blood sugar roller coaster, going a couple days without food is more of a mental challenge than physical hunger.
1. We've acted like nutrition can give the same cut and dry answers that physics has, and the health of our population shows how well that has worked. Worse, nutrition seems to be driven by egos and media in a way that is nothing short of frightening.
>health of our population shows how well that has worked
The average lifespan has gone up considerably in recent decades, and people remain active longer than ever, i.e. people are gaining productive years, not just end-of-life years.
That is almost all due to medical, not nutritional science - antibiotics, better surgeries, pharma, etc. Nutritional science has been an abysmal failure for decades and is barely beginning to relearn many things "nutrional science" itself intentionally threw away in favor of laughably simplistic ideas about how the body works.
I'm going to go out on a limb and say medicine wasn't very effective pre 1900, and furthermore the vast majority of life expectancy improvements were due to clean water and enough food.
Historically, nutrition has saved a ton of lives. But, I'm with you, modern "nutrition science" doesn't really deserve any credit for that.
And ironically, death rates from obesity just crossed those from hunger. The abundance of food (or rather, abysmal diet culture) is now starting to hurt us.
Sure but isn't it misleading to correlate high caloric intake with obesity? I mean this CAN be the case, but the more weight I lose and the more I work out - the more calories I actually consume.
I think it's safe to say that there's some sort of correlation, although of course obesity is a complex issue.
Higher caloric intake is just part of equation. Sedentary life style, increased stress, reduced sleep,
"western" diet (highly inflammatory, with poor nutrient density), craving-inducing food, and messed up intestinal flora are just some of the things that likely contribute to obesity.
As someone who travels from US to Europe often, I always wonder what exactly it is that causes such dramatic difference.
Is it gluten, that's been under scrutiny lately? It doesn't seem to be so, since so many European countries are happily eating their bread. Although European-favored sourdough has been shown to positively affect intestinal flora through fermentation, unlike those puffy bread-like impostors you see in commercial stores in US.
Lifestyle doesn't seem to differ much either, although Europeans definitely have a more sacred and slower approach to meals, and there's less of that "quick lunch in a rush" culture.
However, portion size and difference in cooking oils (olive in EU vs. corn/cottonseed/canola/etc. in US) seem to stand out the most, and are probably the biggest offenders. [1]
There are a number of reports claiming that wheat strains in the US and Europe are quite different, with differing gluten levels. The US has certainly pioneered the breeding of high-gluten wheats, as they're better for processed goods.
Unfortunately, I can't find a reference with any science.
Certainly in Scandinavia wheat does not play the primary role that it does in the US. Rye, barley, and oats are common in the diet. How many Americans, though, have eaten 100% rye bread even once in their lives?
What about ordering/eating out versus preparing your meals from basic ingredients? (including lunch, which we bring in a box or baggy)
That was a big difference I saw while in the US. I hardly ever order/takeout my meals, and when I do, I do it under the assumption that it'll be strictly less healthy than whatever I'd prepare myself (this may not always be true if you're 1 not a very good cook and 2 only order lunch at very health-focused places)
Modern "nutrition science" has saved plenty of lives. It's no where near as important as indoor plumbing, but managing diet often has huge impacts when dealing with many diseases.
I should have made it clearer that I was meaning to refute the claim about [declining] "health of our population", not defending the nutritional science. I don't have much love for the latter.
Well, it is both. Cleaning the water supply has drastically increased infant mortality and general health, which is someways is a nutritional advancement.
I think he's referencing "Lifestyle diseases" or "Diseases of civilization", like diabetes and heart disease, which appear to be quite rare in tribal settings (and not just because people die first of other things), but are commonplace in places like the modern USA.
People are obviously living a lot longer, but it's hard to tease apart how much of that is (1) people not dying of communicable diseases, which used to be the #1 killer, (2) sheer quantity of food (i.e., not starving), (3) the decline of violence, (4) diet composition, and (5) a whole host of other things.
We can't really just say "We're better now than we were then, so every change must have been a good change," without teasing apart correlation from causation. Otherwise in the 60s you could have said "People didn't used to eat lead paint chips, and now they do, and people are living a lot longer these days."
If we were to take this article as truth -- specifically, the part that fasting can activate dormant stem cells, then fasting could very well be a bad thing.
There was recent research done that suggests that stem cells are a key ingredient to long life [1], and if they were to, say, come out of dormancy and become active too early and die, then you have just shortened your life.
Your reply has the same problem as SoftwareMaven's. Claims about two facts which are both true, does not make a correlation. (the only difference between yours and SoftwareMaven's claim is + vs -)
There are way too many factors at hand to be able to say anything about the role/value of nutritional science on the overall lifespan of earthlings.
> There is a lot of evidence beginning to emerge on the value of fasting. This was once encoded in culture as almost every culture had some concept of fasting.
This is a cultural rift between Western Europe and everyone else. I grew up in Eastern Europe (now I live in the US), and fasting was not an extraordinary concept in that culture, by any means. But I keep noticing how controversial it is in the West.
I could probably speculate on the influence of material wealth on culture, and so on, but there's probably not much of a point here.
> I found fasting became much easier after I changed my diet to be ketogenic.
You don't need to go that far. Fasting is easy when you don't do any kind of alimentary excess in general.
I think the whole keto concept is just the pendulum swinging all the way to the other side. I guess it will settle in the middle at some point. Eat a bit of everything, nothing in excess, make sure to not miss the greens and the fruits, etc. Self-control and self-limiting are things that we all need to re-train ourselves for - and not just when it comes to food.
---
Anyway, I'm far more interested in studies regarding the effects of fasting on the brain. Traditionally, it was used in a spiritual context, by people who, for lack of a better term, were consciousness hackers. Fasting seemed to enable that process, whatever the mechanism.
I'm also very curious about the effects of fasting, if any, on neurodegenerative diseases.
The ordinary results of fasting and meditation are visions and hallucinations. It isn't something that should be taken lightly or to an extreme. I had a Christian friend who tried a 30-day fast, he did indeed speak to God and God told him to kill himself. The note he left was basically gibberish. This is not too surprising.
Take a look at what Weston Price learned as he traveled around healthy cultures. I'm certainly not implying "everything old is good", but we have adopted an attitude of "they were all stupid", which isn't true. Let's take a look:
Wisdom: Fat is a good energy source.
"Science": Fat makes you fat and clogs your arteries.
Now: Fat is important for regulating satiety and nervous system health.
Wisdom: Simple carbs and sugar should be very limited.
"Science": You can eat as much as you want without any problems.
Now: High glucose and fructose loads are significant players in NAFLD, diabetes, heart disease and dimentia.
Wisdom: Fermented foods like keifer, sauerkraut, and miso are important parts of the diet.
"Science": Kill all the bugz!
Now: Gut biome health may be a significant factor in many physical and mental health problems.
Wisdom: Regular periods of fasting are good for mind and body.
"Science": You should eat 6 small meals every day to keep blood sugar even.
Now: See TFA.
These are pretty disingenuous, uncited, and generalized examples. For example, fat has always been fine, excess calories are not. That leads to fatty build-up that does cause serious health issues. The problem is that casuals see 'fat' and equate it with body fat, instead of being focused on what science has been saying saying all along: eat that calories you need and not past that as you'll gain weight. Marketers have used this confuse to sell products, "low fat" craze, but that has never been the staple of nutritional understanding.
Lets also remember even the ones that the "ancients" got right, they got millions wrong, most of which were seriously dangerous. The modern person's appeal to the past is insane to me. I think if you could travel back in time to live in one of those cultures you value so much, you'd see nothing but sickness, death, and other horrible things that would be trivially treated in post-enlightenment societies.
Unfortunately, bullshit like 'ancient wisdom' has become popular of late thus parents not vaccinating their children, a return to extreme/fundamentalist religiosity, and dangerous cargo cult-like beliefs like treating cancer with green tea.
This is a mischaracterization of the past 30 years. In the 1980s, American's really were told to drastically reduce their fat intake due to a misunderstanding of LDL. It remains recommended to only be 10% of your daily intake of calories -- a statement of the percentage of calories you should eat as fat, not a statement about excess calories, which can be regarded as bad in general regardless of their source. If you look at what took place in the following 30 years since this stance, fat intake has in fact been reduced quite considerably in the United States, yet heart disease has increased. This has nothing to do with worshiping "ancient wisdom", its simply identifying an error science made (which it is allowed to do), and rectifying it without historical revisionism.
Unfortunately, bullshit like 'ancient wisdom' has become popular of late thus the parents not vaccinating their children, a return to extreme/fundamentalist religiosity, and general dangerous cargo cultness like treating cancer with green tea.
That's a false dichotomy. It is possible to look to ancient practices with an eye towards using those as foundations for research. We didn't do that; instead, we let threw out all of that knowledge, the good and the bad, and we have 100 million sick people in the US and over a billion around the world.
I'm a firm believer that we can find good answers in science, but we are doing a piss-poor job and have been for 50 years. In fact, I'd go so far to see we've done very little nutritional science over the last 50 years; instead, we've done nutritional marketing in white coats. If people are rejecting what nutritional researchers are saying, they have only themselves to blame.
Things have gotten a little better in the last decade, but large organizations like the AHA, ADA, AND, and, of course, the US government, still seem to be stuck following the marketing literature of companies like Conagra and Monsanto rather than the science.
We didn't do that; instead, we let threw out all of that knowledge, the good and the bad, and we have 100 million sick people in the US and over a billion around the world.
I'm not sure what you expected scientists to do. None of the "traditional wisdom" was confirmed as true, it all had to be tested and was considered suspect until such testing had taken place.
On top of that, traditional diets had shortcomings. It's hard to produce enough calories for today's population to survive, without a larger proportion of those calories coming from grains.
Faced with this change in the food landscape, and with faith in traditional wisdoms rightly shaken, nutritionists have been basing their advice on reasoning from first principles, and preliminary results. They got it wrong badly. But at least we were on the path to a better understanding of nutrition. It's been too slow, and nutritionists were not skeptical enough of preliminary results, but lucky us, these are problems science knows how to fix.
There is more involved than just calories. It's surprising that this myth continues to hold, when we understand how differently macronutrients are treated in the body. Calories are a second-order effect: you don't gain weight because you eat too many calories, your body demands more calories because it is hormonally/nutritionally imbalanced and, therefore, shunting energy into fat cells instead of allowing it to be used for energy. And this doesn't get into the fact that a high percentage of chronically ill patients (CVD, diabetes, dimentia) are thin.
Having dealt with being overweight most of my life, I can't help but believe the reason the myth holds on is because it is a way to justify judging fat people as less than skinny people since they just "can't control themselves".
Eat a better macronutrient ratio, and the body responds positively, even for isocaloric diets, whether for weight loss[1] or for maintenance[2]. But, really, isocoloric doesn't mater; what matters is ad libitum eating. Ironically, every study that I've read that compares low carb diets against low fat diets allows ad libitum eating for the low carb but restricts caloric intake for the low fat. Why is that? Even with that constraint, the low carb diets win[3].
3. http://nutrition.stanford.edu/documents/AZ_abstract.pdf (I have a lot of respect for Christopher Gardner. He's a vegetarian who started this study because he believed a vegetarian diet would trounce other diets. It didn't, but he didn't try to game the results. That's an unfortunately rare behavior in nutrition research where so many people seem to be more concerned with proving their idea correct than finding the truth.)
Where do you get from that 'fat has always been fine'? It's been the target of demonization by trendy dietitians for essentially the second half of the 20th century. This article on the subject made it to the top of HN a while ago:
GP is not making a very clear argument, but you are piling on a fat helping of hubris.
First you appear to believe the specious nutritional myth that weight gain is a matter of calories in vs calories expended. Of course that appeals to scientifically-minded due to the comforting immutability of the laws of thermodynamics, but it ignores the fact that the human metabolism and satiety mechanisms are extremely complex and powerful. Even if you had a magic meter of all calories going in and out it wouldn't begin to solve our nutritional problems at a society level.
Second, things like the paleo (little p) approach to diet and health are not about "ancient wisdom". It's about the fact that we evolved under certain conditions, and while those conditions were constantly changing, the rate of change accelerated exponentially after industrialization and have completely been completely decimated in the last 60 years (less than one lifespan). While western medicine has made amazing strides in the last century, nutrition is still very much in its blood-letting dark ages. Looking to ancestral lifestyle clues is just good sense given the paltry information we have available. None of that is to poo-poo the scientific evidence we have, but understand that human nutrition is far too complex for nutritional science to yet provide convincing answers.
A lot of folks around here are so quick to look down their nose to people are too "granola" and make seemingly un-scientifically-subtantiated decisions like not eating processed foods or preferring "natural" or "whole" foods. But you know what? In the lack of sufficient knowledge, these hippies are making far smarter decisions than the geek who decides that since we don't have proof we might as well carry on with the average American diet. We pat ourselves on the back for our scientific literacy and rational decision-making, but deep down we are animals subject to the same conditioning and addicted to the same heavily processed foodstuffs which are almost certainly leading to all kinds of nasty health outcomes. We don't want to change our diet not because it's the rational decision, but because it fucking tastes good.
People don't look down their noses at those who say things like "eating food that has been processed less is probably better for you".
People do, rightly, criticise those who claim problems with diet are all fixed with a single thing - paleo! Keto! No HFCS! No carbs!
Also, it's easy to deride calories out : calories in but it is fundamentally true that if a person eats fewer calories than they use they will lose weight. The fact that some people have gut flora that helps them stay thin and others have gut flora that makes it easier to gain weight and other people have a small genetic influence does not stop CO:CI being true, it just means that CO:CI is very hard to follow for some people. Suggesting that those people receive cognitive behaviour therapy and exercise programs along with lifestyle change to help them lose weight is usually met with stiff disagreement about the efficacy of these evidence based interventions.
CO:CI is impossible to follow period. There is simply no way to measure accurately both ends. It might be useful as a tool to some people, but as an objective solution it's just a banal truism with no reproducible path to success.
Other than that, I'm in complete agreement with what you said.
Science has never said you can eat as many simple carbs as you like with no problem.
There have been "scumbag food advertisers" and "unqualified unregistered pseudo nutritionists" who have said that you must not eat any fat at all but that sugar is fine. That's not science.
The current US government nutritional guidelines call for 6-10 servings of grains per day. It is only in the last 10 years that "whole grains" (white flour with a little bran added back) has been added, but the glycemic index of whole grain bread is almost identical to white bread. Grains are the "foundation" of the food pyramid.
We've also been told for 50 years that sugar is metabolically inert, so you "just have to worry about the calories". Sugar is a fine substitute for anything, just look at Snackwells.
The message has been driven home so well that stupid things happen like a mother getting fined for packing a nutritious lunch for her daughter, but not including the all-important "Ritz" food group[1].
Are you really referencing the US Government's guidelines in the process of arguing how wise our ancestors were compared to today's food science?
You might as well ask Coke and McDonald's about their idea of a food pyramid.
Our ancestors knew exceptionally little about food nutrition. They ate what was naturally available to them, as they had absolutely no alternative. Doing something by default because it's the only option, does not make you wise. Our ancestors were in fact ignorant about nearly anything to do with the properties of food / health / nutrition et al. And they also did incredibly stupid things because of that ignorance, history books are filled with this fact.
Yes, they ate what was available to them. For generations upon generations. Those who survived were usually the ones whose bodies could thrive on that diet. The mankind of today are descendants of those people, with their genetics. So while the idea of a "paleo" lifestyle might be a bit too simplistic, it's vastly better than the USG's current guidelines. If you could just remove refined sugars, starches, and fruit juices from the food pyramid, that'd be a fantastic start. Their negatives vastly outweigh their positives. Whole, unadulterated food products seem to be the way to go.
Every entry in the food guidelines is backed up by reams of scientific references. If the guidelines are well referenced yet can still say whatever Coke and McDonalds want, how can we call that science?
> Every entry in the food guidelines is backed up by reams of scientific references.
Just because something references science doesn't mean its well grounded in it.
> If the guidelines are well referenced yet can still say whatever Coke and McDonalds want, how can we call that science?
We can't. That's the point -- evaluating the merits of science by looking to policy that references but does not reflect science is invalid on its face.
The USG guidelines have been well-founded on scientific research.
If you want to argue that the USG guidelines were founded on scientific research that they (or other government branches) paid for, that they've managed to distort the resulting science to the point of destroying it, and that the whole process has been beholden to large food interests and national interests by virtue of the control of the purse strings... be my guest!
It is, however, what the "science" has been for the past 50 years. There has been no other "science". Attempts to pretend otherwise are simply and straight-up revisionist history, now that real science is finally poking through and the science of the past 50 years is not looking all that good. However, it is our moral duty to not pretend that "science" has been right the past 50 years, has been telling us the same things that we are just figuring out now, and it was, just, uh... umm... very very quiet or something?
Has there been simple experiment - take 10000 well sampled people, put them on the guidelines diet for two years and observe the outcomes compared to the general population.
This line of reasoning is ridiculous and I will give an analogy.
Pick an ancient "wisdom" at random. What probability do you assign to this belief being true? You get "throwing salt over your shoulder increases luck." Obviously ridiculous right? You aren't going to actually do it just cause "the ancients" said it was good.
Now imagine some study comes out saying that exposure to salt in the air actually increases your something-or-other levels making you healthier. Ha, the ancients were right (kinda-sorta, about one thing, and for the wrong reasons, and with the wrong predicted effect)! All modern science must be wrong and all ancient wisdom must be correct! Proof we must go back to draining blood to to treat diseases and stop abandoning ancient practices.
Wisdom: Regular periods of fasting are good for mind and body.
"Science": You should eat 6 small meals every day to keep blood sugar even.
Now: See TFA.
These recommendations don't actually conflict. Maybe it's best to eat lots of small meals when you're eating, and still fast periodically.
sounds like science is doing a fine job, the important thing is that it self-corrects and we have a far, far deeper understanding of subtile complexities.
one of the few things that gives me hope for humanity is the hope that most things we "know" today will (rightly) be wrong in 100 years.
knowledge from conventional wisdom doesn't compound over time.
But that wisdom is all from different periods. Fat in particular is the old sugar - it makes food taste good. It's also the most calorie-dense macronutrient. Of course you're going to put as much as you can in your food. Want some more old wisdom? Bread: eat as much as possible, because it's cheap and fills you up. Bread and butter - the foundation of a good diet.
You can't just take any old practice and follow it blindly, you need to have some idea if it's good for you or simply doesn't kill you. Because there's a whole ton of shit that doesn't kill you.
Nutritional science may be bunk, but at least you can usually tell when they're speaking bunk and it sure beats the old system of "My parents ate this and they lived to the ripe old age of 50".
You know what's funny? Before the 1940s, we didn't really have a problem with obesity, heart disease, diabetes, non-alcoholic fatty liver disease, PCOS, or any number of other diseases tied to diet. The groups that had problems had a diet much like we do today (high in flour and sugar, low in fat) except with less protein.
I'm not saying we can't improve on what was "known", and we can certainly understand the methods of actions. They also got a lot wrong. I'm just looking for a little humility in nutrition science.
So, what did they get wrong?
Smoking is ok (or, maybe even healthy).
Exercise is unhealthy[1].
Making dinner after wiping away black plague puss w/o washing hands is OK.
1. Ironically, the alternative of too much exercise may be unhealthy as well.
The fact that particular traditions exist implies that they might have some net benefit. Otherwise, people who practiced these traditions might have been out-competed by other groups who did not.
> Why would one want to ignore beneficial knowledge received in the form of tradition?
You want to be skeptical of tradition as a source of factual information because, while there exists beneficial knowledge that may be received in the form of tradition, it is impossible to reliably separate it from harmful false "knowledge" received in the form of tradition, without first turning it into knowledge derived from structured scientific information gathering.
> it is impossible to reliably separate it from harmful false "knowledge" received in the form of tradition
Evolution/Survivability of a group usually takes care of that
Yeah, slightly harmful/long term harmful things will go though, but not major things.
Someone discovered cheese with mold is edible (probably happened in a low food situation), but there's a high likelihood on people having tried other things with mold and it didn't work out as expected.
A thousand years ago, it may have been more dangerous to send three times as many villagers to collect water from the river 20km away so that the village would have enough water for everyone to wash their hands, than to have people not wash their hands before eating. The benefits of a practice/tradition can vary over time.
Lots of people may have died from avoidable diseases, but lots of people may also have avoided death by bandits, wild animals, and starvation. (due to more workers allocated to water collection than food production; the extra food produced may have been the difference between life and death during famines for some people.)
Because the past had proportionally more hucksters to scientists than today. And because a lot of that 'ancient wisdom' was invented later, by the aforementioned hucksters:
Because tradition isn't knowledge. While tradition could be (valuable) source of leads, everything inside must be tested, experimented on and see why it does or doesn't work.
That article is perfect example - lots of cultures have fasting. We look at the fasting results and we find something interesting about how out body works. Now we have knowledge that we can build upon.
Beware of pseudoscience. In the past, some things worked, something things didn't, but there's no understanding as to why they did or didn't work out of traditional models.
Scientific models haven't been all that great either, but science hopefully will eventually self correct as nutritional models become more sophisticated. If there is light at the end of the tunnel it will be because of the eventual understanding that the scientific method provides, not reverting back to traditional models.
Traditional models don't self correct and there are plenty of instances of people consuming outright poisons under such systems or people following traditional nutrition models finding themselves surrounded by an abundance of previously rare foods that the modern food supply system easily provides, and practically gorging themselves on it to negative health results.
We have to make decisions now. Do you think the prescriptions from the current state of nutrition science outperform ancestral eating heuristics in real life? I don't, and whether it's true or not is one of the major points under debate. The debate can't automatically be vetoed by invoking "pseudoscience".
As an epistemic issue, I have to use all the evidence available to me. What I've noticed is that human physiology is a dynamic equilibrium of a massive number of variables and the current state of our analytic tools have had immense trouble evaluating it efficiently. Ancestral eating patterns looks like worthwhile evidence under the circumstances.
Incidentally, essentially no one is blindly promoting traditional eating. Folks are using it as a guide and together with science to make decisions in the face of limited understanding. One of the most popular ancestral diet proponents is Stephan Guyenet, a Ph.D. neurobiologist who studies the link between the brain and obesity for a living[1]. Everyone is for science and no side on the issue owns it.
One of the common problems with diets of any kind is that there's an immediate fallacy of an appeal to authority. I'm sure Dr. Guyenet is very qualified as a neurobiologist, but his PhD is not in anything relevant to nutrition (even if he is studying the neurological aspects of eating) -- his B.S. is.
Which means that in theory, any random undergrad in a Biochem major is equally qualified to speak on the subject. This is not to put down Dr. Guyenet's work, it's important as obviously there's a neurological component to many kinds of obesity. But then to extend that work into his advocacy for traditional dietary guidelines is a stretch.
If he was just an undergrad student in Biochemistry with a blog telling you to do all of the things exactly opposite Dr. Guyenet, would you follow that instead? Why not? That person would be just as educationally qualified. I suspect the reason has to do more with what diet you've chosen to follow a priori and not with Dr. Guyenet's advocacy. I'm not going to pick apart specific issues with this blog, but a casual perusal of it shows lots of fad diet advice and logical "appeal to tradition" fallacies. "We should eat this way because people used to eat this way".
The reason people used to eat that way is because they had nothing else available. That's it. There's no secret "the ancients had figured out nutrition from their folk ways" that we should be parroting. There are lots of ingredients in traditional diets that we understand today to be outright poison (like bracken). And lots of ingredients our ancestors thought were poison but are just fine (like potatoes).
Traditionally, people didn't even know what to eat to stop scurvy. A nutritional disease which killed millions and turns out to be trivial to treat.
What we know about good nutrition (using the power of science) happens to be in pretty broad strokes with pockets of ultra-specificity where we've bothered to do serious research. Science has gotten it pretty wrong as well in the past and probably will for some time as the study of nutrition matures. And you're absolutely right, we can't wait 200 years for nutrition science to mature in the way that Physics has, we have to eat today (and multiple times at that).
All I'm saying is that nutrition blogs are a dime a dozen, from people with all kinds of credentials, and lots of them are full of all kinds of advice. "People used to eat this" is just cargo culting dietary advice (and then trying to backfill in justification after the fact) and I would chalk it up to pseudoscience and just make my own decisions based on reasonable advice like "eat in moderation, eat in variety".
As if our ancestors were fasting because they knew it was good for their health. As if their poor nutrition didn't cause much worse problems for them like nutrient deficiencies, lower IQ, shorter heights, lower life expectancies. As if most people today eat only according to the best consensus of nutrition science.
I can second that. Ketosis and fat adaption reduces the need for constant refueling. I have no problem going 24 hours between meals and exercising while fasting.
I typically eat ~12 meals per week, 2000 kcal per meal.
In addition, the consistent mental acuity achieved in ketosis is fantastic.
While science is advancing and giving a better view of what is needed and what can cause problems, the market is replacing most things in the food without much regard for its consequences
Also, science "doesn't know what it doesn't know yet", so we may be missing something that was inconspicuously removed, or suffering from something that was apparently safe
I think it's important to note that "Ketogenic" might not be the right word for the necessary diet intervention to make it easier to fast for long periods.
Ketosis is a state where you eat so little carbohydrate, that your body is forced to create "ketone bodies" to fuel the brain. This typically happens at <50g/day carbohydrate.
Most anecdotal evidence (and my own experiences) show that you can get your body into a primarily fat-burning state that makes it easier to fast for long periods without hunger pangs by eating up to somewhere around 100 or 150g/day carbohydrate (assuming you eat a 2000-2500 Kcal/day diet) while providing enough glucose to the brain that your body is not forced to create excess Ketone bodies.
SoftwareMaven, I will suggest that one possible explanation is that our gut is filled with microbes (some good, some bad) and food is filled with microbes and, by weight, our poop is 50% microbes of some sort. So when you fast, you clean out bugs from your system, some of which are very not good for you. We seem to have lost this idea that we are organic, living creatures, part of a complex biome and seem to have this fantasy that we are merely ...chemically complex and in need of more building blocks. And life is just way, way more complicated than that. It is much closer to an on-going, multi-front battle. And when you never fast, you never take a break from that battle. It just keeps on going.
The more interesting part of this to my eyes was the material difference between 24 hour and 72 hour fasting in human chemotherapy patients, in that the former didn't do anything to the measure of immune cell populations and the latter did. Intermittent fasting is nowhere near as well studied as calorie restriction at this point in time, so it is interesting to see these mechanisms emerge.
Now this is chemotherapy immune suppression, not aging immune dysregulation. I'll be mildly surprised to see the exact same result in people with age-damaged immune systems, as the character of the damage is very different. The animal results for aging rather than chemotherapy here are intriguing but that's all. There's still a lot of work to be done to arrive at the level of comfort with this effect that exists for other aspects of calorie restriction or intermittent fasting.
But given that (a) obtaining human data on fasting and immune cell population in old people is a comparatively low cost study to put together, and (b) the group involved here seems to have a good flow of funding to study intermittent fasting in a broader context, I'd expect to see that data emerge at some point in the next few years.
> The more interesting part of this to my eyes was the material difference between 24 hour and 72 hour fasting in human chemotherapy patients, in that the former didn't do anything to the measure of immune cell populations and the latter did.
If you do zero-calorie fasting, there are some important changes around or after day 3. Hunger disappears. Metabolism is low, muscles are relaxed. The mind tends to more easily stay focused on a single topic. There's a sense of clarity and ease, and an odd kind of energy. It's quite a contrast with the increasingly frantic frustration prior to this time.
This is all from a subjective standpoint, of course, but it's well correlated by most people who have done it. It seems quite obvious that there are major changes around day 3. I'd love to see more data from studies.
Not having read the article, I wonder if this might be a common response in mammals -- if you're too sick to eat for two whole days, immune system "assumes"[1] it's missed something, and tries desperately to get you back to healthy enough to forage/hunt...?
[ed: well, that's entirely wrong, based on the article -- it's the body killing off as much dead weight as possible in order to hang on a bit longer -- then healing back up when food is avaliable. Oh, well :-) ]
[1] By which I mean there is some complex time-delayed protein-signal-avalanche that is somehow tied to long periods without nutrition...
My humble summary based on superficial reading of the paper:
* Prolonged fasting = Eating NOTHING for 48-120 hr.
* BENEFICIAL effect started on cycle 4 (day 39).
* 1 Cycle = 2-4d fasting&chemo; 8-10d recovery.
* Prolonged fasting enhances cellular resistance to
toxins in mice and humans.
* Glycogen depletion required => switch to fat/ketone
bodies-based catabolism (!!!).
* They have no idea, what the effects on blood are
in detail.
* At the beginning WhiteBloodCell count went down.
* After 6 cycles things stabilized.
One of the things I've been up to the last couple years is reducing the divergence between my life and the conditions I probably evolved for. E.g., much less processed food, reduced use of artificial light that diverges from the normal day/night cycle, more frequent modest physical exercise, very low sugar consumption, way less alcohol and caffeine. To me it feels a lot like when I'm debugging a system and am trying to get back to a baseline by eliminating complicating factors.
Lately I've been wondering about fasting in that context. Not eating occasionally was presumably pretty normal for our ancestors. Have other self-hackers here experimented with this?
I don't know that the biological benefits of fasting are associated directly with cultural fasting patterns in our ancestry.
I suspect they're more linked with our ancestral hunter-gatherer traits. It seems logical that early humans would go periods of time without eating while hunting, then consume a large amount of protein and fat in a short period of time.
Religious and cultural fasting, however, would likely have not occurred until the development of language which is estimated at 20k-50k years ago. That's not a particularly long time on an evolutionary scale.
It doesn't need to be the tradition that shaped our biology. It could be our biology that shaped the tradition. Assuming we already have some benefit to fasting, a group who make a tradition of fasting are more likely to survive than a group who does not. Thus the fasting meme takes over as the people who believe in it take over.
I agree that we're probably adapted, in our biology, to re-occurring intervals of food scarcity. I would not be surprised at all if it turned out that our bodies actually function better on that sort of regime (eat at will for a while, then forego all caloric intake for a brief period).
I wonder if this was noticed at the dawn of civilization, and then got codified into religion and so on.
Yeah it's interesting how ancient cultures seemed to have (by trial and error I suppose) incorporated specific behaviors into their culture which, in hindsight, solve a particular problem that can be scientifically identified.
An example I love is the Canadian Inuit who traditionally ate no vegetables for 10+ months of the year without developing scurvy. The tradition of eating raw whale blubber and fish (including the broth) preserved the vitamin C and minerals from the mea, while eating cooked meat without broth drastically reduces mineral and vitamin intake.
From an evolutionary standpoint periods of famine were certainly a selective pressure for our ancestors. It could make sense that prolonged periods of no-food are not only something our bodies have adapted to survive, but have adapted to thrive upon as part of their natural cycle.
Sorry for being nit-picky. It is not that we evolved to thrive during periods of famine. It is that we did not evolve under conditions where resources were plentiful. That is why so many people die from heart conditions brought on by excessive eating. The machinery in our body is simply insufficient to deal with the excess cholesterol.
He's saying that even when people are universally weakened by starvation, the other mutations that exhibit advantages (a regenerative immune system in this case) are rewarded with further generations. I think "evolved to thrive in famine" is fair to say.
It could make sense that prolonged periods of no-food are not only something our bodies have adapted to survive, but have adapted to thrive upon as part of their natural cycle.
How do you make the jump from "Most able to survive famine." to "Thrive on famine."? It doesn't seem obvious to me that we would automatically evolve to the latter result over the former.
Let's look at what the submitted article, which is a press release from a university, says. "In both mice and a Phase 1 human clinical trial, long periods of not eating significantly lowered white blood cell counts. In mice, fasting cycles then 'flipped a regenerative switch,' changing the signaling pathways for hematopoietic stem cells, which are responsible for the generation of blood and immune systems, the research showed."
What's good about this line of research is that it is trying to show whether or not an observation found in a model animal will also be found in human patients. As preliminary research, this will have to be replicated by other researchers before we can rely on this finding (NOT extended fully to human patients in the current study) to guide treatment of human patients.
This is good news that people are investigating this issue. Once there has been a thorough review article on this issue published in a different journal by a different author, summing up several well designed studies, then we will really have something to talk about here on Hacker News.
I should comment on some of the other comments here. One very tricky problem in studies of human nutrition is that there isn't a good model organism for nutrition and its effect on human health. The study reported here, just like most medical intervention studies, begins in a mouse model. Mice are well understood organisms and their similarities to and differences from human beings for many medical treatments are well understood. Mice are not a particularly good model for nutrition studies, however, because mice are rodents (part of a clade of obligate herbivores) while human beings are primates (part of a clade of facultative omnivores). Moreover, human beings, the current species Homo sapiens, have evolved with co-evolution of the gut in the environment of the cultural practice of cooking food.[1] Cooking is a human cultural universal. No other animal lineage has evolved in a similar environment, so no animal provides a fully suitable model for studies of human nutritional interventions.
Human nutrition studies are HARD, because they require minute-by-minute monitoring of the subjects and exact measurements of food intake to gather meaningful experimental data. (I recall a TV news report from the 1970s about a human nutrition study in which the study volunteers, who of course were paid for this, lived confined inside a lab in which lab technicians weighed all their food to the nearest gram and controlled everything they could eat for the duration of the experiment. Alas, I've never heard of results of that study, perhaps because the sample size, with such an expensive procedure, was too small to generate meaningful data.) Yes, let's see what nutritional interventions do what for human beings, but let's be careful not to jump to conclusions too soon, because careful data gathering on this topic is especially difficult, and anecdotes crowd out data in most popular discussion of this topic.
One also has to look at the surrounding studies for context and plausibility, not just this one in isolation. For example, I think you are overcautious in your comments on nutrition data in humans for calorie restriction and fasting - there is in fact quite a large amount of support for both benefits and safety in humans, both in the context of augmenting chemotherapy and as a general health practice. There is further an enormous weight of evidence in various mammal species for the benefits of calorie restriction and fasting.
In the case of this particular item, referring specifically to alterations to the white blood cell counts and lineages, the human data only goes so far as chemotherapy patients, and not very many of them. Talking about age-altered immune systems is premature. It would not be a surprising result if validated by other researchers, as calorie restriction and fasting are already known to beneficially influence immune function over the long term, but the details here should be taken as merely interesting until someone else runs larger studies to obtain more data.
(I recall a TV news report from the 1970s about a human nutrition study in which the study volunteers, who of course were paid for this, lived confined inside a lab in which lab technicians weighed all their food to the nearest gram and controlled everything they could eat for the duration of the experiment. Alas, I've never heard of results of that study, perhaps because the sample size, with such an expensive procedure, was too small to generate meaningful data.)
I am curious what your thoughts are for a reasonable means to gather data here and draw conclusions. Something practical and do-able. Is there anything that you would think was any good?
Is calorie constriction considered nutrition? Of course animals will have evolved different food requirements, but it seems like the basic mechanism of responding to a lack of calories should be the same.
It's not my field, but I would expect it to be. We don't ingest calories, we ingest chemicals that we convert to energy. A term like "calorie constriction" masks the complicated nutrition processes behind this.
You ask a fair question. I think the large difference in body size and considerable difference in "wild" behavior between human beings and mice leaves some room for doubt about whether they share the same responses to fasting. This, of course, is an empirical question, a question the currently reported study is trying to answer in part.
As someone who doesn't know very much about the immune system - I wonder if this 'resetting' property could be used to treat allergies or other minor autoimmune problems.
Also, I'd appreciate a medium-level overview of the immune system, if anyone has a good link.
Anecdotal evidence, for sure (and IANAD/IANYD), but I've found that fasting eliminates my food sensitivities (both water fasts and apple fasts, where you just eat an apple or two a day, have done the trick for me). They eventually come back after a month or so (no science behind it, but it feels like a slow buildup of whatever was initially bothering me), at which point, I can fast again with similar positive result. I find it's safer/healthier than living on Prilosec...
This book[1] is the best resource for a "medium-level" overview I've come across. Once you get beyond that, you're entering textbook and then paper territory.
Pathology resident here, starting a flow cytology rotation next month (diagnosing disease by studying live immune cells with lasers and antibodies). My best advice is to realize this stuff is really complicated. Start by synthesizing your own hematopoietic cell lineage diagram from existing versions (google image search for them) and use that as your foundation when reading texts.
Yes though not a typical presentation of EE (EoE?). It ramped up dramatically around my 24th birthday and appears to be connected with my body's response to histamines. As such most doctors haven't known what to do with me and we've been feeling our way blindly along. If fasting even partially resets immune response i'd be interested.
I'm not familiar with what is out there as far as materials, but I would speculate that beyond that to get an overview you would end up looking at a medical textbook (with shorter treatments being more specific).
Fasting has always been a tradition in many religious groups. It would interesting to study groups that fasted regularly to see what affect it had on longevity.
Calorie restricted diets have been extensively studied. Radically reducing your food intake is about the only known way to seriously extend lifespan. The trend holds true for virtually every multi-cellular organism ever tested under laboratory conditions.
But it doesn't seem likely that this is what our biology is adapted to.
I think we're primed to function at optimum parameters on a baseline food abundance, punctuated by brief intervals of scarcity. I think that's a much better model for how our very distant ancestors lived. I don't think we're the descendants of those who lived in scarcity all the time. But it's quite likely that the hunting-gathering life had its periods of lean caloric intake regularly.
I wonder if that would still be true among animals that are allowed to eat whatever they want to eat, and given plenty of space and others to interact with.
I'm not positive, but I would bet that a big confounder to these results would be that we are feeding all individuals in the study an unhealthy, unnatural diet, isolating them, or causing stress. These factors could cause them to eat too much.
> "In contrast to the conclusions reached by the University of Wisconsin–Madison (WNPRC) study, a 2012 National Institute on Aging (NIA) study published in the journal Nature, concluded that a calorie restriction regimen did not improve survival outcomes whether implemented in young or older age rhesus monkeys.[49] A key difference between the WNPRC and the NIA studies is that the monkeys in the WNPRC study were fed a more unhealthy diet.[50]"
Reducing one's calorie intake by 30% long-term seems highly unlikely for most people. I do wonder how many of the benefits can be had by just reducing glycation by reducing the amount of simple sugars one consumes.
AS a religious practice I would fast one day a week from sunset to sunset.
(Ancient day was from sunset to sunset) But mainly that was an easy thing to do. I only drank water. I would also do some three or four day and I am mad at myself for not practicing fasting more often. I could think so much better and was a great form of self-discipline.
Most modern Christians have a wacky idea of fasting. Most do not go water only. Several will drink liquid juices and other liquid foods. No idea why???? Or there is the weird modern invention called the "Daniel Fast" which equals eating Kosher in the Bible but in practice it is eating like a vegetarian for a few days or weeks. No idea how this happened.
I'll recommend fasting with fellow Muslim friends and co-workers for a day during Ramadan. it is very rewarding and revealing about our daily routines and eating habits. I enjoy high productivity during Ramadan, plus it is healthy.
You know I've had a hunch for a while there must be something to these "detox" diets where you just eat a bunch of carrots or whatever. I think it's increasingly clear collateral fasting is the answer. The gimmick is "it's the carrots", the reality is you're inducing an extended fasting state which has all kinds of beneficial impacts on the body.
The science is increasingly clear that humans should be putting their body in a fasting state far more often and for far longer than we in the decadent west do.
Wonder if you can approximate the effect with regular blood donations? It's my understanding that regular blood donations are a good idea for males because it helps clear out old red blood cells with iron buildups. Clearing out old white blood cells could be yet another motivator.
You joke, but I have a condition where my iron content builds up relatively quickly, and the best thing they've still figured out as a cure is blood letting.
These are just nervous jokes following the ongoing demise of antibiotics. But, having to resort to venipuncture for treatment of hemochromatosis must be tough. Hope your phlebotomist also prescribed some chelating agents to reduce frequency of treatment.
I have heard of this, and I think that is probably the only modern reason for blood letting. I think there is a similar condition in people who get frequent blood transfusions.
Certain body systems only activate certain processes when the body isn't processing food. Firstly, the gut is an immune organ. Think of it this way: this inside of the digestive system is technically outside the body. It is a continuous tube mouth to anus, and functions as an interface between the outside world and systemic circulation - both blood and lymphatic. The gut has GALT - Gut-Associated Lymphoid Tissue [1]. Lymphatic tissue is an immune system organ and a waste disposal system [2].
It's important to note that all (most) fats are first absorbed by the GALT (specically Lacteals [3]), where it then takes some time to enter blood circulation - the Thorasic Duct [4] (largest lymph vessel) drains in to the Subclavian Vein [5] - so any fat soluble toxins (as in, fat soluble non-nutrients and / or outright toxic molecules) are absorbed by the GALT and removed by white blood cells. Only when this system isn't being stressed by our regular (and typically poor) food intake can the immune system attend to it's ordinary tasks of dealing with regular cellular waste products.
Aditionally, Caffeine consumption reduces immune activity [6]. Alcohol (ethanol) is a Type 1 / Group A carcinogen [7] - why doesn't alcohol packaging state this in the same way cigarette packaging does (in Australia, at least).
Full Disclosure: this is my field of expertise, I hold an Advanced Diploma in Clinical Nutrition from an Australian Nationally Accredit Training organisation. I have been actively studying this field for over ten years.
Aside from the non-sense of miracles etc., it has been a tradition in yogis in India to fast regularly. Maybe the positive effects were observed/known even in those older times.
The article seems pretty obvious. If you don't eat food, your body will eat itself. It would make sense for it to eat the worst cells first. Then when you add new food into the system it can replace those cells.
Perhaps fasting was more common in the past, so it was a reliable trigger for this behavior, and our bodies did not need to develop their own automatic trigger. Why waste resources rebuilding things, after all?
I've been eating 1 meal a day for the past 2.5 years and have not been sick since (usually I'd get a few colds each year) plus I always feel great. I'd like to think I'm getting the benefit of an improved immune system such as in this article, but I guess time will tell.
No. Expertise and authority is an excellent way to evaluate claims. In this case, monks and holy men have espoused so many crazy and harmful ideas over the years that knowing they have endorsed [all kinds of fasting, not just the ones being evaluated scientifically] is not useful because their endorsements have no connection to the truth.
Sadly, that research didn't pan out. One paper has been retracted and the other likely will be. I haven't followed it closely, but I understand there were some significant issues with edited images and results not being reproducible.
Had there been no references cited by chirsBob, this comment would be an overall negative "hearsay"-type contribution, but the inclusion of a reasonably reputable, if outdated, reference allowed others to point out the paper retraction, and raised the overall quality of the discussion.
No, actually I submitted it knowing that the paper had been retracted, and was stirring up trouble. The down votes are perfectly reasonable in this case.
I do appreciate the defense though as some times is is hard to tell which posts were inaccurate by mistakes, and which were malicious. [edited to thank the defending post]
On a personal note, I found fasting became much easier after I changed my diet to be ketogenic. With a metabolism primed for burning fat for energy and not subject to a blood sugar roller coaster, going a couple days without food is more of a mental challenge than physical hunger.
1. We've acted like nutrition can give the same cut and dry answers that physics has, and the health of our population shows how well that has worked. Worse, nutrition seems to be driven by egos and media in a way that is nothing short of frightening.