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The Effects of Intermittent Fasting on Human and Animal Health

202 points by joubert 11y ago

doublerebel 11y ago
Besides the science, IF is great as a 'lifestyle' diet. It's a simple way to balance food and exercise through awareness and knowledge rather than fads or short-term programs. I think that's why it's caught on well with lifehackers.
- ak1394 11y ago
  This. It removes so much of cognitive load compared to other diets. You don't have to care about choosing your food according to the diet or to count calories. You don't have to figure out if you are withing the limits of the diet, or feel bad if you've eaten something extra. On the days you're not fasting, you can eat whatever you want.
  - ThrustVectoring 11y ago
    The cognitive load is really the hard part of dieting and weight loss. In one sense, weight loss is simple physics - calories in vs calories out. In another, food is fundamentally connected to our motivation centers, and dieting is a ridiculously complicated affair to align your long-term goals with the emotional effects of eating.
ponytech 11y ago
tl;dr ?
- ExpiredLink 11y ago
  see 'Abstract'
- phloxicon 11y ago
  Abstract An increasing number of animal studies have shown altered markers for health in subjects exposed to intermittent fasting, i.e. regularly and repeatedly abstaining from eating during 12-36 hours per period. It has been hypothesized that the reported beneficial health effects from caloric restriction on excess body weight, cardiovascular risk factors, glucose metabolism, tumor physiology, neurodegenerative pathology and life span can be mimicked by alternating periods of short term fasting with periods of refeeding, without deliberately altering the total caloric intake. Therefore, a systematic review of available intervention studies on intermittent fasting and animal and human health was performed. In rodents, intermittent fasting exhibits beneficial effects including decreased body weight, improved cardiovascular health and glucose regulation, enhanced neuronal health, decreased cancer risk and increased life span – some of the effects independent of the effects attributed to calorie restriction alone. The human studies performed to date are generally of low-quality design. Beneficial effects such as weight loss, reduced risk for cardiovascular disease and improved insulin sensitivity have been observed, but conflicting data exists. The potential health promoting effects of intermittent fasting in humans and applicability to modern lifestyle are discussed. - See more at: http://www.lift-heavy.com/intermittent-fasting/#sthash.HPQDELwJ.dpuf http://www.lift-heavy.com/intermittent-fasting/#sthash.HPQDE...
- mfringel 11y ago
  I'm afraid I don't understand your question. It is for you to decide whether it was too long, and whether you didn't read it because it was too long.
alexchilcott 11y ago
It's a shame that by self publishing this, the work has not had any kind of peer review. As a relative layman, I have no idea how much I can trust the method or conclusions presented.
- kiba 11y ago
  I trust replications more than peer reviews. With replication, somebody has to actually try and duplicate experiments.
  - _Wintermute 11y ago
    Replication without proper controls is just confirming a poorly designed experiment.
    - simonh 11y ago
      That's true to a point, but replicability really is the cornerstone of science. A replicable result, even if it's ridiculously implausible, at least needs to be properly investigated to see where the mistake lies. There's something there that is investigable (is that a word?). Conversely you can have all the controls and peer review you like, but if the result isn't replicable it's garbage. Just nicely presented, plausible garbage which frankly is the most insidious and dangerous kind. There have been some interesting studies into replicating results from published research that have found that only a very small fraction of peer reviewed papers present actually replicable results. That's shocking.
- taigeair 11y ago
  Yeah I also don't know why this is the case because it would be more credible and prestigious. His reason was: First, the idea was publication in a scientific magazine. For many reasons, taking time from becoming a good clinician being the most important, but far from single one, I eventually decided not to go that route.
- spuz 11y ago
  How often are research/litrature reviews peer reviewed? All the references are there, you can check them youself with little effort. There are no results that need to be replicated. To verify no bias exists in the presentation of the existing research, you'd basically have to reproduce the entire output of this paper (i.e. go and find and report on every single study out there related to fasting to ensure the results have been fairly presented). That's not so much a review as a replication of the research and I cannot see how a journal would have the resources to do that. What benefits would peer review give in this case?
PhilWright 11y ago
TL;DR There might be something in it but nobody really knows because no one has studied it properly.
- spuz 11y ago
  That's a very poor TL;DR. There have been many studies involving animal responses to fasting. There have been fewer human studies due to the difficulty of performing controled studies on humans but reading this report will give you an idea of where the data is lacking. Saying 'no one has studied it properly' comes across as a little unfair.
  - PhilWright 11y ago
    Fair point, maybe I was a little harsh. But I think people reading the headline just want to know if it works. Is there something to it? The answer is, come back in a few years and maybe we will have an answer.
bonestamp2 11y ago
My grandma has been doing IF (without knowing it's IF) for the last 50 years. She's 94 now and apart from her mind, she's in very good health for her age. I know it's completely anecdotal, but I do believe IF is part of her success.
- wozniacki 11y ago
  Could you perhaps add more detail to this? Did she drink? smoke? Was she a pescatarian? or her diet consist of lots of leafy greens? Lived in conditions closesly resembling a blue zone[1]? Anything else besides the IF that was out of the ordinary in her regimen? [1] Blue Zone https://en.wikipedia.org/wiki/Blue_Zone https://en.wikipedia.org/wiki/Blue_Zone
- cb18 11y ago
  How did she unintentionally start IF? Just not eating breakfast or dinner I guess, but do you know if there was any particular reason she chose or was required to do that?
nness 11y ago
I wonder if a 12-36 hour period is consistent with the frequency in which predators hunt. I can't imagine a lion eating every few hours. Anyone knowledgable on things like that?
sfjailbird 11y ago
Besides the proposed health benefits, it is worth also considering the effects on mental/emotional state. It is probably no coincidence that fasting is an element of practically every traditional religious and spiritual practice. As an example, in Islam the recommended practice is to fast two times a week (consistent with the regimen the OP discusses). Things that work well for the physical body usually has a corollary beneficial effect on mental state, which is no less of an upside than the health benefits.
- hoers 11y ago
  In this case it seems to be even more than 'just' corollary, there are tons of papers being published about the connection between inflammation (which fasting seems to mediate very effectively) and a whole array of mental diseases
- 4ydx 11y ago
  Whether or not it is a coincidence mentioning religion adds nothing to the conversation.
  - pennaMan 11y ago
    I disagree. It's worth mentioning simply because the practice has survived a long time trough many cultures. Time is a really good curator - if something survives a really long time (thousand of years scale) it is very likely to be of use.
    - dylanjermiah 11y ago
      >Time is a really good curator - if something survives a really long time (thousand of years scale) it is very likely to be of use. Do you have any evidence to support this theory? I very much doubt this holds any truth. Time is not an indication of truth, empirical evidence is.
      - mfringel 11y ago
        How is "a practice that has been sustained across multiple cultures over thousands of years" not empirical evidence?
icemelt8 11y ago
Its the month of Ramadan, fasting for 30 days
- dylanjermiah 11y ago
  An important difference for Ramadan is that it does not allow the consumption of water.
- mandazi 11y ago
  Same here. Half way through. 2 weeks left. Kinda sad it's going by so fast.
roebk 11y ago
The BBC produced a documentary on the fasting titled Eat, Fast and Live Longer, it's well worth a watch - http://www.dailymotion.com/video/xvdbtt_eat-fast-live-longer-hd_shortfilms http://www.dailymotion.com/video/xvdbtt_eat-fast-live-longer...
krautsourced 11y ago
Just from completely personal experience I can confirm the positive effects - if paired with good food and exercise. I've been doing IF for roughly 3 months now (16 hours fast per day, which is pretty easy to do by skipping breakfast) and combined it with leaving out all the crappy food I ate. You know, the usual gaming/coding/convenience stuff like chips. That and regular sports (rowing) not only resulted in weigh loss (which most likely was just from reduced calorie count, not IF per se) and strongly improved blood pressure (from high to normal). So, at least in my case, the combination of the three factors made a massive difference. At the same time, I doubt IF by itself would do much if during the rest of the time you ate 3000 calories from chocolate and chips.
- hoers 11y ago
  Just out of curiosity: do you substitute your breakfast with something? I'm on a stinging nettle + mate tea combination but slowly need something new for my taste buds
  - andy_ppp 11y ago
    I make a nice tea with Ginger, Fresh Turmeric Root, Cloves and Cinnamon. It tastes amazing :-)
  - xerula 11y ago
    There's a whole world of fine and unusual teas to discover and enjoy. When I fast, I want a tea that provides more meaty aromas and a more complex taste experience – a food substitute that also gives a 'cleansing' sensation. (It's hard to be precise about what I mean by 'cleansing', but something like the opposite of the typical cloying English breakfast black tea). A fine kabusecha or gyokuro with their intense umami flavors can provide that. At the moment I have some Japanese 'bancha goishicha', a wildly different style from the green teas made from the same plants, a strange and strangely delicious double-fermented tea with tangy seaweed and mushroomy notes that is like a meal in itself.
- ak1394 11y ago
  Same here, although I skip entire days not eating. Also, I think it get's easier to go without food for a day after a couple of months doing it. I would attribute the improvement in blood pressure to an exercise, not IF (at least this was my case, as I've started going to gym before I started IF and seen the blood pressure drop).
Brotkrumen 11y ago
https://news.osu.edu/news/2015/05/19/skipping-meals/ https://news.osu.edu/news/2015/05/19/skipping-meals/ That study suggests (i think) that mice on the 24h fast developed insulin resistance in the liver, a sign of prediabetes. Since I actually like the one-meal-a-day lifestyle, I wonder which study is more applicable to humans...
Kurtz79 11y ago
I have done IF as part of a weight loss program (basically I save 90%+ of my allowed calories for a single daily meal). I also went through more traditional programs, where calories are spread more evenly over different meals throughout the day. In my experience both methods work very well, especially if paired with exercise, and I couldn't really see any difference in terms of health benefits. Personally though, I found that the IF works better from a psychological standpoint, and I'm more likely to stick to it longer: the single meal I have tends to be much more satisfying and allows for appetizing foods and quantities that I could not afford if spreading the daily allowance on more meals.
empressplay 11y ago
i havent regulariy eaten breakfast since i was a child. glad to find out what i thought was a bad habit might have been a good one!
torgoguys 11y ago
I'm not hostile to the concept, of intermittent fasting (IF), quite the opposite, but I don't think there is much useful information (as the public) we can get from this paper. Granted, I've only skimmed, but there are problems. The paper isn't peer-reviewed and the author indicates he doesn't feel inclined to attempt to get the paper reviewed/published. Red flag. But that doesn't matter anyway because he reaches only weak conclusions, indicating the data in humans is murky. The author clearly believes IF is beneficial anyway and writes as if he is an advocate for it in the intro at the top of the web page, before the paper appears. Even more damning, portions of the paper itself read like they were written by an advocate. He just couldn't help himself. His job there is to attempt to be neutral and discover and summarize what the data shows (with conclusions) for his systematic review. However, this paper can serves as a handy compilation of references on the subject which could help other researchers. Given the author's advocacy of the subject, if used as such care should be taken to ensure the references are thorough and nothing is omitted.
- spuz 11y ago
  What part made you believe the author was an advocate for IF? I didn't get that at all.
  - mattlutze 11y ago
    It is, quite simply, the tagline of his website[1] that the OP linked from: "Strength Training & Intermittent Fasting At Its Best" [1]: http://www.lift-heavy.com/ http://www.lift-heavy.com/
  - scrapcode 11y ago
    I also got that vibe in a paragraph preceding the paper that has a Clickbank affiliate link to a book on the subject of intermittent fasting. The author goes on to state "...it has helped many people get leaner and healthier with a relaxed mindset." That kind of hinted to me where the bias of the paper would be. However, such bias could've resulted from the information he found during his studies.
  - pbreit 11y ago
buserror 11y ago
I rather often fast for a lot longer than 16h; I think the 'day fast' is a pretty rough deal, as the hunger (ie, the down side of fasting) is strongest on the first day. So really a small fast isnt too interesting, as you get all the disadvantage without much in terms of advantages. By the second day, you are no longer hungry anyway, so, for me, a 3 day fast is next to ideal. But I can do rather easily 5 days. I mostly start on the monday morning and finish on friday, or saturday if I feel brave and there's nothing too exciting in the fridge! As to why do do it? Well I like cooking, and eating, and drinking, and I rather hate counting calories and such, I'm much more of a 'on/off' sort of guy, and I rather like a bit of a challenge. That also helps me control my weight, without having to spend stupid amount of time in the gym. Also, there /is/ a 'high' to a fast, I feel like on the third and fourth day you feel particularly sharper; it then decline a bit and you can feel a bit woozy. But the high is pretty cool...
- bch 11y ago
  So, what does pass your lips during a fast period?
  - buserror 11y ago
    Fruit juice cut with water, and some coffee (there are bleeping limits! ;-))
    - odiroot 11y ago
      Fruit juice is sugar. It's debatable then if it's a real IF.
      - buserror 11y ago
        I'm not really trying to do it 'by the book' -- I think it's better that you come up with something that works for you. Fasting with just water is a bit tough, as you can get a metallic taste in your mouth that is rather disagreeable. So that's my 'fix' for that problem.
ilitirit 11y ago
I haven't had breakfast since about 2007. Well, of course there are days where I do have it when I'm staying over at a hotel, or I'm at an early work function. But I don't make breakfast for myself at home. My first meal is between 12h30 and 13h30. I don't feel any worse (or better) than when I used to eat breakfast in the past, but it's been so long that I really can't tell. I suppose this can be considered a type of fasting because of the length of time between lunch and supper the previous night. I've never really understood the idea that breakfast is the most important meal of the day because I've never suffered from any ailments because not eating breakfast. Or maybe I have and I just don't know it? But then I could apply that same logic to times when I got inexplicably ill or just was not performing at my peak and I did have breakfast. My point is that I don't notice any significant changes in my health and or behaviour. Of course I don't advise anyone doing this (or NOT doing - check with your physician first), but I still firmly believe that there is a lot of about diet and fitness that has to do with the physiology of the individual. (BTW, if anyone else thought the linked article sounded familiar it might be because you've read it already. It was published 1 year ago)
- megablast 11y ago
  I started to skip breakfast a few years ago. Now I skip lunch as well. Feel a lot better for it, don't lose energy, and don't get tired in the afternoon. I run everyday in the morning instead of breakfast, and cycle a lot.
- ak1394 11y ago
  I normally don't have any breakfast either, just because I prefer to spend extra time in bed in the mornings. This haven't prevented me from gaining weight though. So just skipping breakfasts in the long term wouldn't be enough.
- morganvachon 11y ago
  > I've never really understood the idea that breakfast is the most important meal of the day... I've always heard that you should have the most calories and greatest diversity of food at the first meal of the day, slightly less so at the midday meal, and a very light/low calorie dinner. This is supposedly because you need that huge energy and mental boost to get your day started, and as the day goes on your caloric intake should taper off as you won't need it as much by the time you get home from work, and a light dinner because within a few hours you'll be sleeping and won't need it either. Now that being said, it wouldn't work for me. I am up around 6-6:30am, I have breakfast (when I do eat it) at 7:15-7:30am, and my morning at work is decidedly not busy nor does it require critical thinking (I'm basically stuck answering the sales lines in the morning as the rest of the team doesn't roll into work until nearly lunchtime). This is off-season, so I might get ten calls before lunch, and about half of those are non-productive. I take an early lunch, around 11:30am, so I'm available for the larger part of the afternoon. So, the time between breakfast and lunch is usually four hours. That's not enough time to fully digest a large breakfast and be hungry again, so I usually either eat a light breakfast or none at all. What I've found is that if I eat small meals for breakfast and lunch, with a snack available should I need it in the mid afternoon, I tend to focus better and get more done. The only downside is that by the time I get home and finish cooking dinner, I'm ravenous and I end up eating way too much for that meal. That's the part I'm trying to focus on now and cut down to about half. This will put my overall caloric intake at less than the "maintain" level for my build and age, which will hopefully help me to slowly lose weight.
wooger 11y ago
FWIW, I've done a ~20 hour fast for the last few months. Eating in a 4 hour window from 6pm to 10pm approx. This diet isn't practical if you're doing any serious exercise, either in the morning, or late evening (during after the eating window), so I often have to cheat and eat lunch, or otherwise extend the window on days when I'm exercising. Otherwise it's surprising easy to stick to with a coffee or two for comfort, and I've lost a significant amount of weight: * It's hard to eat enough calories to gain / maintain my (over)weight in 4 hours, at least if I stick to whole, fresh, real food. Some days I can hit a ~1000 calory deficit according to my calculations. * I find it easy to go to sleep on a full-ish stomach, which helps a great deal compared to other diets.
- swalsh 11y ago
  I maintained a 1500 calorie diet for a year a few years ago. I'd pretty much just skip lunch every other day, and on the days I ate i'd go to chipotle and get hardshell tacos with just the fajita peppers, lettuce, and the mild salsa. By skipping the cheese, meat, and beans the calorie count is VERY low. Eventually I lost 30 pounds. It's not the crazy amounts some people lost, but it was significant for me. Today though, 1500 seems to be my normal. If I go much above it, I start to gain. I think that's the risk of doing it this way. Your body seems to get used to the reduced count for some reason.
  - klue07 11y ago
    > Your body seems to get used to the reduced count for some reason. It's called "starvation response." Being at a caloric deficit for a long period of time makes your body think that it is going to starve to death. Therefore it reduces your metabolism in response to the lack of calories you intake. This is why having a cheat day every once in a while is actually physically good for your body not just psychologically.
    - capisce 11y ago
      Maybe this reduced metabolism is good for longevity?
hiou 11y ago
When is HN going to get a penalty filter for all these health fad/craze links? They just bring out all the crazies and the articles are typically inconclusive at best and opinionated and divisive at worst.
- TheCapn 11y ago
  I agree with you man. For a site that's geared towards technology blogs there's a huge amount of health articles on here. Not only that, but like you said it attracts a lot of fervent personality types who portray a lot of the cult-like attitudes towards a certain diet or program (Keto is especially bad). Way too much speculation from programmers who think they're outsmarting an entire industry of health professionals. I have a particular hatred for Soylent but thankfully its quick rise to popularity has drawn upon it a lot of scrutiny and with that has alleviated a lot of the bad that it was originally representing. I still think there are superior alternatives on the market that have pre-dated Soylent but the fact that its been iterated and improved by health professionals and not a Software Engineer says a lot for it.
- mwfunk 11y ago
  I agree with you although this particular article seems far better than most. Anecdotally (my personal experience, with zero statistical significance), the last 10 years seems like it had a huge explosion of interest in fad diets among twenty- and thirtysomething tech industry people. Not sure if this is an actual trend or just a consequence of where I live and who I spend time with these days. I'm solidly middle-aged at this point. When I was in my 20s and 30s, there were just as many fad diets and nutritional voodoo but it was generally super credulous, spacey middle-aged and older people that were into them. The phenomenon of a degreed, professional 23-year-old wanting to have long and enthusiastic conversations with me about the properties of gluten (or whatever) in casual social contexts feels really bizarre. This is a very roundabout way of saying that for whatever reason, at this point in time there is a big overlap between people who are into voodoo health crazes and the core HN demographic. This seems like a recent trend to me, but that's only anecdotal.
subpixel 11y ago
A really interesting BBC show on the subject of intermittent fasting: http://www.bbc.co.uk/iplayer/episode/b01lxyzc/horizon-20122013-3-eat-fast-and-live-longer http://www.bbc.co.uk/iplayer/episode/b01lxyzc/horizon-201220... I've been experimenting with alternate-day fasting for a while now. I allow myself whatever I want for breakfast (usually cereal with fruit, or oatmeal) and then I eat _basically_ nothing until breakfast the next day. If I really want one, I'll eat a banana or a grapefruit after a run. An interesting observation is that I have absolutely no problem exercising on fast days. In fact a 5m run feels great.
rickdale 11y ago
July 2 marked 2 years straight only eating from 6pm-10pm with bullet-proof coffee sometimes during the day. I grew up always needing food and I can attest that my body adapted to eating this way and totally changed when I started eating this way in the sense of strength and lean muscle. Generally I eat pretty clean, lots vegetables meat beans and lentils, with a cheat day once per week, but always within my eating window. I try to drink a lot of water during the day too. I am conscious that the water is reverse osmosis and then I'll add a pinch of celtic sea salt, some apple cider vinegar, and lemon. I also use active h2 tablets which I highly recommend.
- stephengillie 11y ago
  Have you had the same work hours for 2 years straight? That seems somewhat uncommon, unless you've worked at the same place in the same position for that long. My current schedule, I would be asleep for most of your eating window. In the past 6 years, my working schedule has rotated around the entire 24 hour clock - early morning shifts, midday shifts, swing shift, early overnight shift, late overnight shift. My eating rotates around with my work shift, eating a small meal before work, a small one during (whenever during the day or night the shift is, there's a "lunch" break almost in the exact center) and a large meal after work.
  - sprkyco 11y ago
    4.6 years was the average tenure of an employee in 2014. 2+ years straight is within the parameters of common. http://www.bls.gov/news.release/tenure.nr0.htm http://www.bls.gov/news.release/tenure.nr0.htm
annasaru 11y ago
I am 5.8, 135 lbs. I'm convinced I can be lose another 10lbs if I cut down slightly, and keep running twice a week. Down to my college or high-school weight if I drop another 10 lbs. It would reduce my cardiovascular risk, improve my running (easier on knees). Am not a Muslim, but this month of Ramzan (or Ramadan) does inspire me to try some light fasting. Nothing severe, no extremes for me. Happy with incremental, over a period of time, changes.
- bkmartin 11y ago
  I'm wondering why you feel the need to lose 10 more lbs? It feels like an arbitrary number. Besides 135 lbs for someone who is 5.8 is a very healthy weight. You are exercising regularly which is great, so you are probably not likely to reduce cardiovascular risk much more, if that can even be quantified realistically at this point. Running is hard on your knees, period. If you want to go easier on your knees maybe take up biking or swimming.
jmnicolas 11y ago
I tried fasting last year after reading a book that promised health "miracles". At first I fasted every Monday for 3 months (no food at all just water), then I fasted for 14 days without interruption. This is much easier than I was thinking. After 3 days I was not hungry anymore BUT I wanted to eat. What I mean is that I had no pain in my stomach but my mind wanted the comfort of eating something. It grew more and more, at the end I was watching Youtube cooking videos every evening and planning all the great meals I would cook once I restarted to eat ;-) Physically I could have lasted at least 2 weeks more, but mentally I was tired of it. I'm a software dev I so of course I had it easy compared to someone who has an active lifestyle. Now for the bad part : no health miracle at all, and all the weight I lost has been regained and then some. And since then I was unable to gather enough willpower to fast again, even for just one day.
- cfeduke 11y ago
  > no health miracle at all, and all the weight I lost has been regained and then some Lifestyle changes that impact health require that one habitual adopt the change to realize their benefits long term. Of course if you followed a fasting program just once and then returned to the same habits you had prior to fasting you should expect to gain weight back. Really it just means that if you want some health change you need to find something that is appealing so you can form a habit. (I don't find fasting appealing either.)
deleted 11y ago
[deleted]
zw123456 11y ago
The biggest problem with these types of theories (e.g. Paleo diet, grazing, micro-eating etc.) is that there is no way to test against a placebo, for obvious reasons. So it is really impossible to completely test the theory scientifically.
- lkrubner 11y ago
  That is not a problem with animal studies. The control groups typically eat however much they want, whereas the control group is starved.
- aroberge 11y ago
  > it is really impossible to completely test the theory scientifically. This shows a misunderstanding of what science is about. You can set up control groups, that use different eating methods, but consuming the same amount of calories (and micro nutrients, etc.) over a given period of time. In some settings, double-blind experiments (with placebos) are indeed "better"; but it is not required to get scientifically valid results.
  - zw123456 11y ago
    True, I may have over stated my point. A double blind with placebos test is the gold standard, and difficult to implement with humans when it comes to diets. Which is why I think there are so many different kinds of fad diets that come and go, which is sort of the point I was driving at. It is just really difficult to conclusively prove.
    - palmer_eldritch 11y ago
      I think the main problem is that people are looking for some kind of silver bullet diet that will make them healthy and live long. So, since there's demand, there are other people providing them with it. Of course it's just air, there's no such thing as a silver bullet diet. Health and longevity depends on so much more than just diet that there will never be such a thing. But still, since there's money to be made by selling dummies miracle diets, there are some to sell. And since they can't sell the real thing because it can't be made, they do what they can to convince the customers that it is. Among other marketing tricks, pervert science so it looks like their snake oil is based on something more than just the will to make money from gullible people. There might be some good science in the nutrition field. Sadly, it's drowned in a sea of wishful thinking, bad science and plain charlatanry...
arjn 11y ago
I wonder if anyone has done a study of the health positive/negative effects of fasting on observant Copts and Ethiopian Orthodox Christians. Respectively their fasting days are approx. 220 and 250 days per year :- https://en.wikipedia.org/wiki/Fasting_and_abstinence_of_the_Coptic_Orthodox_Church_of_Alexandria#General_dietary_rules https://en.wikipedia.org/wiki/Fasting_and_abstinence_of_the_... https://en.wikipedia.org/wiki/Ethiopian_Orthodox_Tewahedo_Church#Practices https://en.wikipedia.org/wiki/Ethiopian_Orthodox_Tewahedo_Ch... and beliefs

202 points by joubert 11y ago

Besides the science, IF is great as a 'lifestyle' diet. It's a simple way to balance food and exercise through awareness and knowledge rather than fads or short-term programs. I think that's why it's caught on well with lifehackers.

ak1394 11y ago
This. It removes so much of cognitive load compared to other diets. You don't have to care about choosing your food according to the diet or to count calories. You don't have to figure out if you are withing the limits of the diet, or feel bad if you've eaten something extra. On the days you're not fasting, you can eat whatever you want.
- ThrustVectoring 11y ago
  The cognitive load is really the hard part of dieting and weight loss. In one sense, weight loss is simple physics - calories in vs calories out. In another, food is fundamentally connected to our motivation centers, and dieting is a ridiculously complicated affair to align your long-term goals with the emotional effects of eating.

ponytech 11y ago

tl;dr ?

ExpiredLink 11y ago
see 'Abstract'
phloxicon 11y ago
Abstract An increasing number of animal studies have shown altered markers for health in subjects exposed to intermittent fasting, i.e. regularly and repeatedly abstaining from eating during 12-36 hours per period. It has been hypothesized that the reported beneficial health effects from caloric restriction on excess body weight, cardiovascular risk factors, glucose metabolism, tumor physiology, neurodegenerative pathology and life span can be mimicked by alternating periods of short term fasting with periods of refeeding, without deliberately altering the total caloric intake. Therefore, a systematic review of available intervention studies on intermittent fasting and animal and human health was performed. In rodents, intermittent fasting exhibits beneficial effects including decreased body weight, improved cardiovascular health and glucose regulation, enhanced neuronal health, decreased cancer risk and increased life span – some of the effects independent of the effects attributed to calorie restriction alone. The human studies performed to date are generally of low-quality design. Beneficial effects such as weight loss, reduced risk for cardiovascular disease and improved insulin sensitivity have been observed, but conflicting data exists. The potential health promoting effects of intermittent fasting in humans and applicability to modern lifestyle are discussed. - See more at: http://www.lift-heavy.com/intermittent-fasting/#sthash.HPQDELwJ.dpuf http://www.lift-heavy.com/intermittent-fasting/#sthash.HPQDE...
mfringel 11y ago
I'm afraid I don't understand your question. It is for you to decide whether it was too long, and whether you didn't read it because it was too long.

alexchilcott 11y ago

It's a shame that by self publishing this, the work has not had any kind of peer review. As a relative layman, I have no idea how much I can trust the method or conclusions presented.

kiba 11y ago
I trust replications more than peer reviews. With replication, somebody has to actually try and duplicate experiments.
- _Wintermute 11y ago
  Replication without proper controls is just confirming a poorly designed experiment.
  - simonh 11y ago
    That's true to a point, but replicability really is the cornerstone of science. A replicable result, even if it's ridiculously implausible, at least needs to be properly investigated to see where the mistake lies. There's something there that is investigable (is that a word?). Conversely you can have all the controls and peer review you like, but if the result isn't replicable it's garbage. Just nicely presented, plausible garbage which frankly is the most insidious and dangerous kind. There have been some interesting studies into replicating results from published research that have found that only a very small fraction of peer reviewed papers present actually replicable results. That's shocking.
taigeair 11y ago
Yeah I also don't know why this is the case because it would be more credible and prestigious. His reason was: First, the idea was publication in a scientific magazine. For many reasons, taking time from becoming a good clinician being the most important, but far from single one, I eventually decided not to go that route.
spuz 11y ago
How often are research/litrature reviews peer reviewed? All the references are there, you can check them youself with little effort. There are no results that need to be replicated. To verify no bias exists in the presentation of the existing research, you'd basically have to reproduce the entire output of this paper (i.e. go and find and report on every single study out there related to fasting to ensure the results have been fairly presented). That's not so much a review as a replication of the research and I cannot see how a journal would have the resources to do that. What benefits would peer review give in this case?

PhilWright 11y ago

TL;DR There might be something in it but nobody really knows because no one has studied it properly.

spuz 11y ago
That's a very poor TL;DR. There have been many studies involving animal responses to fasting. There have been fewer human studies due to the difficulty of performing controled studies on humans but reading this report will give you an idea of where the data is lacking. Saying 'no one has studied it properly' comes across as a little unfair.
- PhilWright 11y ago
  Fair point, maybe I was a little harsh. But I think people reading the headline just want to know if it works. Is there something to it? The answer is, come back in a few years and maybe we will have an answer.

bonestamp2 11y ago

My grandma has been doing IF (without knowing it's IF) for the last 50 years. She's 94 now and apart from her mind, she's in very good health for her age. I know it's completely anecdotal, but I do believe IF is part of her success.

wozniacki 11y ago
Could you perhaps add more detail to this? Did she drink? smoke? Was she a pescatarian? or her diet consist of lots of leafy greens? Lived in conditions closesly resembling a blue zone[1]? Anything else besides the IF that was out of the ordinary in her regimen? [1] Blue Zone https://en.wikipedia.org/wiki/Blue_Zone https://en.wikipedia.org/wiki/Blue_Zone
cb18 11y ago
How did she unintentionally start IF? Just not eating breakfast or dinner I guess, but do you know if there was any particular reason she chose or was required to do that?

nness 11y ago

I wonder if a 12-36 hour period is consistent with the frequency in which predators hunt. I can't imagine a lion eating every few hours. Anyone knowledgable on things like that?

sfjailbird 11y ago

Besides the proposed health benefits, it is worth also considering the effects on mental/emotional state. It is probably no coincidence that fasting is an element of practically every traditional religious and spiritual practice. As an example, in Islam the recommended practice is to fast two times a week (consistent with the regimen the OP discusses). Things that work well for the physical body usually has a corollary beneficial effect on mental state, which is no less of an upside than the health benefits.

hoers 11y ago
In this case it seems to be even more than 'just' corollary, there are tons of papers being published about the connection between inflammation (which fasting seems to mediate very effectively) and a whole array of mental diseases
4ydx 11y ago
Whether or not it is a coincidence mentioning religion adds nothing to the conversation.
- pennaMan 11y ago
  I disagree. It's worth mentioning simply because the practice has survived a long time trough many cultures. Time is a really good curator - if something survives a really long time (thousand of years scale) it is very likely to be of use.
  - dylanjermiah 11y ago
    >Time is a really good curator - if something survives a really long time (thousand of years scale) it is very likely to be of use. Do you have any evidence to support this theory? I very much doubt this holds any truth. Time is not an indication of truth, empirical evidence is.
    - mfringel 11y ago
      How is "a practice that has been sustained across multiple cultures over thousands of years" not empirical evidence?

icemelt8 11y ago

Its the month of Ramadan, fasting for 30 days

dylanjermiah 11y ago
An important difference for Ramadan is that it does not allow the consumption of water.
mandazi 11y ago
Same here. Half way through. 2 weeks left. Kinda sad it's going by so fast.

roebk 11y ago

The BBC produced a documentary on the fasting titled Eat, Fast and Live Longer, it's well worth a watch - http://www.dailymotion.com/video/xvdbtt_eat-fast-live-longer-hd_shortfilms http://www.dailymotion.com/video/xvdbtt_eat-fast-live-longer...

krautsourced 11y ago

Just from completely personal experience I can confirm the positive effects - if paired with good food and exercise. I've been doing IF for roughly 3 months now (16 hours fast per day, which is pretty easy to do by skipping breakfast) and combined it with leaving out all the crappy food I ate. You know, the usual gaming/coding/convenience stuff like chips. That and regular sports (rowing) not only resulted in weigh loss (which most likely was just from reduced calorie count, not IF per se) and strongly improved blood pressure (from high to normal). So, at least in my case, the combination of the three factors made a massive difference. At the same time, I doubt IF by itself would do much if during the rest of the time you ate 3000 calories from chocolate and chips.

hoers 11y ago
Just out of curiosity: do you substitute your breakfast with something? I'm on a stinging nettle + mate tea combination but slowly need something new for my taste buds
- andy_ppp 11y ago
  I make a nice tea with Ginger, Fresh Turmeric Root, Cloves and Cinnamon. It tastes amazing :-)
- xerula 11y ago
  There's a whole world of fine and unusual teas to discover and enjoy. When I fast, I want a tea that provides more meaty aromas and a more complex taste experience – a food substitute that also gives a 'cleansing' sensation. (It's hard to be precise about what I mean by 'cleansing', but something like the opposite of the typical cloying English breakfast black tea). A fine kabusecha or gyokuro with their intense umami flavors can provide that. At the moment I have some Japanese 'bancha goishicha', a wildly different style from the green teas made from the same plants, a strange and strangely delicious double-fermented tea with tangy seaweed and mushroomy notes that is like a meal in itself.
ak1394 11y ago
Same here, although I skip entire days not eating. Also, I think it get's easier to go without food for a day after a couple of months doing it. I would attribute the improvement in blood pressure to an exercise, not IF (at least this was my case, as I've started going to gym before I started IF and seen the blood pressure drop).

Brotkrumen 11y ago

https://news.osu.edu/news/2015/05/19/skipping-meals/ https://news.osu.edu/news/2015/05/19/skipping-meals/ That study suggests (i think) that mice on the 24h fast developed insulin resistance in the liver, a sign of prediabetes. Since I actually like the one-meal-a-day lifestyle, I wonder which study is more applicable to humans...

Kurtz79 11y ago

I have done IF as part of a weight loss program (basically I save 90%+ of my allowed calories for a single daily meal). I also went through more traditional programs, where calories are spread more evenly over different meals throughout the day. In my experience both methods work very well, especially if paired with exercise, and I couldn't really see any difference in terms of health benefits. Personally though, I found that the IF works better from a psychological standpoint, and I'm more likely to stick to it longer: the single meal I have tends to be much more satisfying and allows for appetizing foods and quantities that I could not afford if spreading the daily allowance on more meals.

empressplay 11y ago

i havent regulariy eaten breakfast since i was a child. glad to find out what i thought was a bad habit might have been a good one!

torgoguys 11y ago

I'm not hostile to the concept, of intermittent fasting (IF), quite the opposite, but I don't think there is much useful information (as the public) we can get from this paper. Granted, I've only skimmed, but there are problems. The paper isn't peer-reviewed and the author indicates he doesn't feel inclined to attempt to get the paper reviewed/published. Red flag. But that doesn't matter anyway because he reaches only weak conclusions, indicating the data in humans is murky. The author clearly believes IF is beneficial anyway and writes as if he is an advocate for it in the intro at the top of the web page, before the paper appears. Even more damning, portions of the paper itself read like they were written by an advocate. He just couldn't help himself. His job there is to attempt to be neutral and discover and summarize what the data shows (with conclusions) for his systematic review. However, this paper can serves as a handy compilation of references on the subject which could help other researchers. Given the author's advocacy of the subject, if used as such care should be taken to ensure the references are thorough and nothing is omitted.

spuz 11y ago
What part made you believe the author was an advocate for IF? I didn't get that at all.
- mattlutze 11y ago
  It is, quite simply, the tagline of his website[1] that the OP linked from: "Strength Training & Intermittent Fasting At Its Best" [1]: http://www.lift-heavy.com/ http://www.lift-heavy.com/
- scrapcode 11y ago
  I also got that vibe in a paragraph preceding the paper that has a Clickbank affiliate link to a book on the subject of intermittent fasting. The author goes on to state "...it has helped many people get leaner and healthier with a relaxed mindset." That kind of hinted to me where the bias of the paper would be. However, such bias could've resulted from the information he found during his studies.
- pbreit 11y ago

buserror 11y ago

I rather often fast for a lot longer than 16h; I think the 'day fast' is a pretty rough deal, as the hunger (ie, the down side of fasting) is strongest on the first day. So really a small fast isnt too interesting, as you get all the disadvantage without much in terms of advantages. By the second day, you are no longer hungry anyway, so, for me, a 3 day fast is next to ideal. But I can do rather easily 5 days. I mostly start on the monday morning and finish on friday, or saturday if I feel brave and there's nothing too exciting in the fridge! As to why do do it? Well I like cooking, and eating, and drinking, and I rather hate counting calories and such, I'm much more of a 'on/off' sort of guy, and I rather like a bit of a challenge. That also helps me control my weight, without having to spend stupid amount of time in the gym. Also, there /is/ a 'high' to a fast, I feel like on the third and fourth day you feel particularly sharper; it then decline a bit and you can feel a bit woozy. But the high is pretty cool...

bch 11y ago
So, what does pass your lips during a fast period?
- buserror 11y ago
  Fruit juice cut with water, and some coffee (there are bleeping limits! ;-))
  - odiroot 11y ago
    Fruit juice is sugar. It's debatable then if it's a real IF.
    - buserror 11y ago
      I'm not really trying to do it 'by the book' -- I think it's better that you come up with something that works for you. Fasting with just water is a bit tough, as you can get a metallic taste in your mouth that is rather disagreeable. So that's my 'fix' for that problem.

ilitirit 11y ago

I haven't had breakfast since about 2007. Well, of course there are days where I do have it when I'm staying over at a hotel, or I'm at an early work function. But I don't make breakfast for myself at home. My first meal is between 12h30 and 13h30. I don't feel any worse (or better) than when I used to eat breakfast in the past, but it's been so long that I really can't tell. I suppose this can be considered a type of fasting because of the length of time between lunch and supper the previous night. I've never really understood the idea that breakfast is the most important meal of the day because I've never suffered from any ailments because not eating breakfast. Or maybe I have and I just don't know it? But then I could apply that same logic to times when I got inexplicably ill or just was not performing at my peak and I did have breakfast. My point is that I don't notice any significant changes in my health and or behaviour. Of course I don't advise anyone doing this (or NOT doing - check with your physician first), but I still firmly believe that there is a lot of about diet and fitness that has to do with the physiology of the individual. (BTW, if anyone else thought the linked article sounded familiar it might be because you've read it already. It was published 1 year ago)

megablast 11y ago
I started to skip breakfast a few years ago. Now I skip lunch as well. Feel a lot better for it, don't lose energy, and don't get tired in the afternoon. I run everyday in the morning instead of breakfast, and cycle a lot.
ak1394 11y ago
I normally don't have any breakfast either, just because I prefer to spend extra time in bed in the mornings. This haven't prevented me from gaining weight though. So just skipping breakfasts in the long term wouldn't be enough.
morganvachon 11y ago
> I've never really understood the idea that breakfast is the most important meal of the day... I've always heard that you should have the most calories and greatest diversity of food at the first meal of the day, slightly less so at the midday meal, and a very light/low calorie dinner. This is supposedly because you need that huge energy and mental boost to get your day started, and as the day goes on your caloric intake should taper off as you won't need it as much by the time you get home from work, and a light dinner because within a few hours you'll be sleeping and won't need it either. Now that being said, it wouldn't work for me. I am up around 6-6:30am, I have breakfast (when I do eat it) at 7:15-7:30am, and my morning at work is decidedly not busy nor does it require critical thinking (I'm basically stuck answering the sales lines in the morning as the rest of the team doesn't roll into work until nearly lunchtime). This is off-season, so I might get ten calls before lunch, and about half of those are non-productive. I take an early lunch, around 11:30am, so I'm available for the larger part of the afternoon. So, the time between breakfast and lunch is usually four hours. That's not enough time to fully digest a large breakfast and be hungry again, so I usually either eat a light breakfast or none at all. What I've found is that if I eat small meals for breakfast and lunch, with a snack available should I need it in the mid afternoon, I tend to focus better and get more done. The only downside is that by the time I get home and finish cooking dinner, I'm ravenous and I end up eating way too much for that meal. That's the part I'm trying to focus on now and cut down to about half. This will put my overall caloric intake at less than the "maintain" level for my build and age, which will hopefully help me to slowly lose weight.

wooger 11y ago

FWIW, I've done a ~20 hour fast for the last few months. Eating in a 4 hour window from 6pm to 10pm approx. This diet isn't practical if you're doing any serious exercise, either in the morning, or late evening (during after the eating window), so I often have to cheat and eat lunch, or otherwise extend the window on days when I'm exercising. Otherwise it's surprising easy to stick to with a coffee or two for comfort, and I've lost a significant amount of weight: * It's hard to eat enough calories to gain / maintain my (over)weight in 4 hours, at least if I stick to whole, fresh, real food. Some days I can hit a ~1000 calory deficit according to my calculations. * I find it easy to go to sleep on a full-ish stomach, which helps a great deal compared to other diets.

swalsh 11y ago
I maintained a 1500 calorie diet for a year a few years ago. I'd pretty much just skip lunch every other day, and on the days I ate i'd go to chipotle and get hardshell tacos with just the fajita peppers, lettuce, and the mild salsa. By skipping the cheese, meat, and beans the calorie count is VERY low. Eventually I lost 30 pounds. It's not the crazy amounts some people lost, but it was significant for me. Today though, 1500 seems to be my normal. If I go much above it, I start to gain. I think that's the risk of doing it this way. Your body seems to get used to the reduced count for some reason.
- klue07 11y ago
  > Your body seems to get used to the reduced count for some reason. It's called "starvation response." Being at a caloric deficit for a long period of time makes your body think that it is going to starve to death. Therefore it reduces your metabolism in response to the lack of calories you intake. This is why having a cheat day every once in a while is actually physically good for your body not just psychologically.
  - capisce 11y ago
    Maybe this reduced metabolism is good for longevity?

hiou 11y ago

When is HN going to get a penalty filter for all these health fad/craze links? They just bring out all the crazies and the articles are typically inconclusive at best and opinionated and divisive at worst.

TheCapn 11y ago
I agree with you man. For a site that's geared towards technology blogs there's a huge amount of health articles on here. Not only that, but like you said it attracts a lot of fervent personality types who portray a lot of the cult-like attitudes towards a certain diet or program (Keto is especially bad). Way too much speculation from programmers who think they're outsmarting an entire industry of health professionals. I have a particular hatred for Soylent but thankfully its quick rise to popularity has drawn upon it a lot of scrutiny and with that has alleviated a lot of the bad that it was originally representing. I still think there are superior alternatives on the market that have pre-dated Soylent but the fact that its been iterated and improved by health professionals and not a Software Engineer says a lot for it.
mwfunk 11y ago
I agree with you although this particular article seems far better than most. Anecdotally (my personal experience, with zero statistical significance), the last 10 years seems like it had a huge explosion of interest in fad diets among twenty- and thirtysomething tech industry people. Not sure if this is an actual trend or just a consequence of where I live and who I spend time with these days. I'm solidly middle-aged at this point. When I was in my 20s and 30s, there were just as many fad diets and nutritional voodoo but it was generally super credulous, spacey middle-aged and older people that were into them. The phenomenon of a degreed, professional 23-year-old wanting to have long and enthusiastic conversations with me about the properties of gluten (or whatever) in casual social contexts feels really bizarre. This is a very roundabout way of saying that for whatever reason, at this point in time there is a big overlap between people who are into voodoo health crazes and the core HN demographic. This seems like a recent trend to me, but that's only anecdotal.

subpixel 11y ago

A really interesting BBC show on the subject of intermittent fasting: http://www.bbc.co.uk/iplayer/episode/b01lxyzc/horizon-20122013-3-eat-fast-and-live-longer http://www.bbc.co.uk/iplayer/episode/b01lxyzc/horizon-201220... I've been experimenting with alternate-day fasting for a while now. I allow myself whatever I want for breakfast (usually cereal with fruit, or oatmeal) and then I eat _basically_ nothing until breakfast the next day. If I really want one, I'll eat a banana or a grapefruit after a run. An interesting observation is that I have absolutely no problem exercising on fast days. In fact a 5m run feels great.

rickdale 11y ago

July 2 marked 2 years straight only eating from 6pm-10pm with bullet-proof coffee sometimes during the day. I grew up always needing food and I can attest that my body adapted to eating this way and totally changed when I started eating this way in the sense of strength and lean muscle. Generally I eat pretty clean, lots vegetables meat beans and lentils, with a cheat day once per week, but always within my eating window. I try to drink a lot of water during the day too. I am conscious that the water is reverse osmosis and then I'll add a pinch of celtic sea salt, some apple cider vinegar, and lemon. I also use active h2 tablets which I highly recommend.

stephengillie 11y ago
Have you had the same work hours for 2 years straight? That seems somewhat uncommon, unless you've worked at the same place in the same position for that long. My current schedule, I would be asleep for most of your eating window. In the past 6 years, my working schedule has rotated around the entire 24 hour clock - early morning shifts, midday shifts, swing shift, early overnight shift, late overnight shift. My eating rotates around with my work shift, eating a small meal before work, a small one during (whenever during the day or night the shift is, there's a "lunch" break almost in the exact center) and a large meal after work.
- sprkyco 11y ago
  4.6 years was the average tenure of an employee in 2014. 2+ years straight is within the parameters of common. http://www.bls.gov/news.release/tenure.nr0.htm http://www.bls.gov/news.release/tenure.nr0.htm

annasaru 11y ago

I am 5.8, 135 lbs. I'm convinced I can be lose another 10lbs if I cut down slightly, and keep running twice a week. Down to my college or high-school weight if I drop another 10 lbs. It would reduce my cardiovascular risk, improve my running (easier on knees). Am not a Muslim, but this month of Ramzan (or Ramadan) does inspire me to try some light fasting. Nothing severe, no extremes for me. Happy with incremental, over a period of time, changes.

bkmartin 11y ago
I'm wondering why you feel the need to lose 10 more lbs? It feels like an arbitrary number. Besides 135 lbs for someone who is 5.8 is a very healthy weight. You are exercising regularly which is great, so you are probably not likely to reduce cardiovascular risk much more, if that can even be quantified realistically at this point. Running is hard on your knees, period. If you want to go easier on your knees maybe take up biking or swimming.

jmnicolas 11y ago

I tried fasting last year after reading a book that promised health "miracles". At first I fasted every Monday for 3 months (no food at all just water), then I fasted for 14 days without interruption. This is much easier than I was thinking. After 3 days I was not hungry anymore BUT I wanted to eat. What I mean is that I had no pain in my stomach but my mind wanted the comfort of eating something. It grew more and more, at the end I was watching Youtube cooking videos every evening and planning all the great meals I would cook once I restarted to eat ;-) Physically I could have lasted at least 2 weeks more, but mentally I was tired of it. I'm a software dev I so of course I had it easy compared to someone who has an active lifestyle. Now for the bad part : no health miracle at all, and all the weight I lost has been regained and then some. And since then I was unable to gather enough willpower to fast again, even for just one day.

cfeduke 11y ago
> no health miracle at all, and all the weight I lost has been regained and then some Lifestyle changes that impact health require that one habitual adopt the change to realize their benefits long term. Of course if you followed a fasting program just once and then returned to the same habits you had prior to fasting you should expect to gain weight back. Really it just means that if you want some health change you need to find something that is appealing so you can form a habit. (I don't find fasting appealing either.)

deleted 11y ago

[deleted]

zw123456 11y ago

The biggest problem with these types of theories (e.g. Paleo diet, grazing, micro-eating etc.) is that there is no way to test against a placebo, for obvious reasons. So it is really impossible to completely test the theory scientifically.

lkrubner 11y ago
That is not a problem with animal studies. The control groups typically eat however much they want, whereas the control group is starved.
aroberge 11y ago
> it is really impossible to completely test the theory scientifically. This shows a misunderstanding of what science is about. You can set up control groups, that use different eating methods, but consuming the same amount of calories (and micro nutrients, etc.) over a given period of time. In some settings, double-blind experiments (with placebos) are indeed "better"; but it is not required to get scientifically valid results.
- zw123456 11y ago
  True, I may have over stated my point. A double blind with placebos test is the gold standard, and difficult to implement with humans when it comes to diets. Which is why I think there are so many different kinds of fad diets that come and go, which is sort of the point I was driving at. It is just really difficult to conclusively prove.
  - palmer_eldritch 11y ago
    I think the main problem is that people are looking for some kind of silver bullet diet that will make them healthy and live long. So, since there's demand, there are other people providing them with it. Of course it's just air, there's no such thing as a silver bullet diet. Health and longevity depends on so much more than just diet that there will never be such a thing. But still, since there's money to be made by selling dummies miracle diets, there are some to sell. And since they can't sell the real thing because it can't be made, they do what they can to convince the customers that it is. Among other marketing tricks, pervert science so it looks like their snake oil is based on something more than just the will to make money from gullible people. There might be some good science in the nutrition field. Sadly, it's drowned in a sea of wishful thinking, bad science and plain charlatanry...

arjn 11y ago

I wonder if anyone has done a study of the health positive/negative effects of fasting on observant Copts and Ethiopian Orthodox Christians. Respectively their fasting days are approx. 220 and 250 days per year :- https://en.wikipedia.org/wiki/Fasting_and_abstinence_of_the_Coptic_Orthodox_Church_of_Alexandria#General_dietary_rules https://en.wikipedia.org/wiki/Fasting_and_abstinence_of_the_... https://en.wikipedia.org/wiki/Ethiopian_Orthodox_Tewahedo_Church#Practices https://en.wikipedia.org/wiki/Ethiopian_Orthodox_Tewahedo_Ch... and beliefs