19 ms·

Science of Fasting

221 points by sumanmd 4y ago

sumanmd 4y ago
My detailed write up on fasting/caloric restriction and necessary adjustments we need to emphasize in our current daily dietary regimen and this possibly helps keep the metabolic and other diseases at bay, especially in at risk populations(south Asian).
- deleted 4y ago
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mensetmanusman 4y ago
Black coffee and water from 5 am to 6 pm, eat from 6-9 pm works for me. Meals definitely taste better after that window :) I find I sometimes have like two dinners at 6 and 8 which is interesting…
- Dig1t 4y ago
  Very interesting, do you know the total calories you generally eat during that window?
  - sumanmd 4y ago
    Less than 500 - 800 cal and no carbs for 2 days.
- siavosh 4y ago
  I did this for two years, lost a fair bit of weight. But the gorging at dinner time really messed up my cholesterol levels. So just an advice that one's weight isn't the only metric of health, if you do any diet change consult your doctor, and confirm health across multiple dimensions (blood tests etc). Today, I do a heart healthy diet, and try to fast from 8PM-12PM (eat between 12PM-8PM). This helps me not eat/snack unhealthily in a condensed period of time.
  - kmeraz 4y ago
    Curious, what was it about gorging at dinner time that messed up your cholesterol levels? Was it because you'd gorge on foods high in cholesterol, or was there another mechanism at play?
    - itchyouch 4y ago
      My doctor gave me A cursory explanation so I can’t vouch for my limited understanding. That said, cholesterol is essential for the production of bile which breaks down foods. Late night foods probably equates to excess cholesterol released to break down said foods and higher cholesterol levels. We probably want to have periods of fasting in order to not produce excess cholesterol.
      - melissalobos 4y ago
        > cholesterol is essential for the production of bile which breaks down foods So maybe the person fasting had higher cholesterol levels due to his body needing more bile immediately to breakdown a larger amount of food at once? I am very much not a doctor or at all educated in these topics.
      - sumanmd 4y ago
        There are multiple mechanisms as play when we discuss about cholesterol. I will do an article discussing about this in the future.
    - siavosh 4y ago
      I probably implied more causation than I meant. I know nothing about fasting causing my high cholesterol directly. What I do know is I thought my weight not going up liberated me into eating whatever my heart desired in my 4-5 hour feeding window. This feast/famine mentality did me no good given my personality type and I probably ended up eating a lot more food and snacks than I would of otherwise.
  - sumanmd 4y ago
    Great. Congratulations on you IF journey.
- jjtheblunt 4y ago
  Do you not burn up your stomach from the acidity of that diet?
  - jstx1 4y ago
    Do you mean because of the coffee? I drink several cups of strong black coffee on an empty stomach every day and I've never had any problems whatsoever.
    - jjtheblunt 4y ago
      That's awesome, and, yes, that's what i wondered; personally i couldn't, presumably different from person to person. Thanks.
      - Melatonic 4y ago
        It varies a ton per person - I know that I often, for example, end up with the opposite of acid reflux (essentially my stomach is too basic). I would have similar symptoms and take an antacid and it would make it immediately WORSE. Not sure if this is why but I am also one of those people that can eat super acidic foods all day no problem - I can drink black coffee and follow that up with a bunch of citrus and feel great.
        jjtheblunt 4y ago
        oh wow, i'm the opposite: non diluted coffee and i burn, even got scoped and showed gastritis...i evidently am at the acidic end, or just not healed enough, in a vicious burn cycle perhaps...
        Melatonic 4y ago
        The HN news hoardes will probably be here soon to chastise me for even remotely giving health advice over the internet but when I had an ulcer I found out that in Japan doctors will actually prescribe powdered Glutamine (its just an amino acid - common building block of protein - so pretty damn safe) for ulcers and many things that involve the lining of the GI tract. Apparently the walls can directly use glutamine to help repair themselves. Seems to help me a lot and I just regularly started taking small amounts of it daily since I sometimes love eating an exorbitant amount of spicy food and that can be pretty harsh on your insides.
- motohagiography 4y ago
  Am on same one meal a day scheme (espressos in morning, nothing but dinner) for a year and love it. However, it's literally just replacing 2/3 meals out of my day with multiple servings of a highly addictive stimulant. Obviously I'm fine, but I am sure our descendents will look back on coffee as some kind of traditional folk-meth.
  - sumanmd 4y ago
    Great!
- zemvpferreira 4y ago
  Worth it to point out that coffee (and anything you ingest really, including water) will activate bits of your metabolism and having it will not be equivalent to a complete fast for certain purposes. Not that you're wrong having it, just something to realize. Will almost certainly have a negligible or even positive effect on weight loss.
  - robbiep 4y ago
    Generally (and certainly most of the recent fasting trends) fasting is referred to as no more than 500 kcal intake, which is of course different to a ‘true’ definition which would be nothing, except maybe water
    - gretch 4y ago
      500 Calories!? That’s so much. 1 large boiled egg is 80 Calories. So like eat 5 or 6 eggs and you haven’t broken your fast??
      - sumanmd 4y ago
        500 cal doesn't constitute for water only fasts.
      - maccard 4y ago
        500 calories is my breakfast most days. that's not a fast!
    - sumanmd 4y ago
      Fasting definition keeps changing. There is water only and then there is water only and less than 500 Cal.
    - ycombinete 4y ago
      I guess that depends. 500 calories is 1/3 of my wife’s maintenance calories.
  - sumanmd 4y ago
- sumanmd 4y ago
  Interesting, whatever works !
- qqqwerty 4y ago
  Just as a word of warning, acidic coffee and late night eating are two habits heavily associated with acid reflux/GERD. I had similar habits, was relatively healthy, and rarely if ever suffered from heart burn. But about a year ago, seemingly overnight, I came down with severe acid reflux. I am still managing symptoms to this day. Not saying it will happen to you, but just raising awareness that human health is a fickle thing and it can take a turn for the worse quickly, often with little to no warning.
  - mensetmanusman 4y ago
    Good point, I do eat a lot of yogurt and salad and stay away from super greasy foods to prevent reflux :)
- seer 4y ago
  I’ve found eating once a day to be quite tough on the finances. We often eat out, so instead of ordering just dinner, I get all my calories from that one meal, which ends up being quite expensive. So at least for me fasting turned out more expensive :-D On the plus side, I like to try different dishes, as I’m a very curious eater, and now I don’t have to feel guilty when I do.
  - mensetmanusman 4y ago
    You should pregame with a pint of greek yogurt!
hobo_mark 4y ago
After eating only dinner for years, a month ago I found myself eating every other day (except for two pieces of fruit in the afternoon) and I feel even better since then? Where is the limit?
- melissalobos 4y ago
  > Where is the limit? You lose roughly ~0.75 lbs of body fat at normal fasting levels assuming a reasonably active regular sized person. So how ever many days worth of body fat you would like to gain and lose regularly. You would have to eat back the same amount and probably wouldn't want to gorge yourself too much. A reasonable practical limit might be 5 days. All of that assumes that you want to maintain a set weight. So the real limit is how much you want to eat in a single sitting. Take those calories and average them across as many days as needed to maintain weight.
  - angrais 4y ago
    Can you explain the .75lbs number you provided? How often do you anticipate a person to lose that much? Care to provide literature for your claims?
    - melissalobos 4y ago
      1lb of body fat is ~3500 calories. An average person doing average things burns around 2000 calories. You can easily put in your own numbers and get your own results. Just calculate your TDEE(total daily energy expenditure) and look up how many calories in a pound of fat to whatever tolerance you want.
    - db65edfc7996 4y ago
      Not the GP, but a pound of fat = 3500 kCal. If you use the standard 2000 kCal / day basis, that gets you to .57 lbs fat loss per day. Also, the 450 pound (204 kg) man who did not eat for an entire year [0] lost 0.72 pounds / day. [0] https://pmj.bmj.com/content/49/569/203 https://pmj.bmj.com/content/49/569/203
c54 4y ago
I've been long exposed to the standard tech-circles common knowledge about intermittent fasting (IF), the benefits of fasting, basic gym science about calorie restriction, and so on. I thought a lot of this stuff was pretty well confirmed by science as well as various fasting-oriented traditions around the world. Fast one day a week, live longer. Work IF into your eating schedule, increase your productivity and give your body time to 'clean up' your system. But I was surprised to recently realize how novel a lot of fasting research is, and how unconfirmed a lot of the benefits are. Even the wikipedia page for fasting doesn't have as much as I'd really like to see. It's nice to see posts like this one, but even this doubles down on "there are studies in progress" without any convincing completed studies. Review studies such as this[0] one basically confirm in so many words that "additional trials are needed" and while IF can help you lose weight "whether IF itself affects cancer-related metabolic and molecular pathways remains unanswered" It's curiously similar to woo-woo or religious habits and self-help advice: similar in being fringe from the perspective of scientific medicine. But the same groups who I'd expect to be pro-science (for example more likely to get vaccinated) are often mixed up in fasting stuff which isn't (yet) confirmed. I suppose it's not too unheard of to see tech circles overlap with fringe medicine. Check out r/nootropics for instance. Now, I've experimented with nootropics and various supplements. I don't use the term 'fringe' as a haughty outsider. I'm quite willing to consider that it's "not yet confirmed" protoscience, and that this is different from falsified or counter-indicated "remedies" and bits of fringe medicine, things like homeopathy. But it's curious nonetheless. [0] https://acsjournals.onlinelibrary.wiley.com/doi/10.3322/caac.21694 https://acsjournals.onlinelibrary.wiley.com/doi/10.3322/caac...
- tashoecraft 4y ago
  I think a large part of the problem is we may never have big studies for this. It’s very difficult to do human trials, you can’t just lock people up and restrict their calories for years on end.
  - mountainboy 4y ago
    the bigger question is: who would pay for such studies? big pharma? government lobbied by big pharma? universities given grants from government lobbied by big pharma? actually though, the soviets did do serious research into the science/benefits of fasting. Too bad it never really made it to the west. Watch the video: "The Science of Fasting" for an overview.
taytus 4y ago
I've been fasting for 25 years. It's called being poor.
photochemsyn 4y ago
How about the combined effect of intermittent fasting and exercise regimes? One thing I've heard is that fasting lowers metabolism, so perhaps one meal in the morning followed by endurance exercise later in the day would counteract that tendency.
- BlargMcLarg 4y ago
  Science actually suggests fasting increases metabolism, or at least keeps it stable, unlike general caloric restriction.
- giraffe_lady 4y ago
  Sounds really unpleasant honestly. I pretty frequently eat only one insufficient meal/day or fully fast for non-health reasons and there's no getting around the fact that exercise on those days fucking sucks. If there's any benefit I can't see it being worth it except in extreme cases. Particularly endurance exercise without calories afterwards is one of the worst things you can do to your day.
- tibbar 4y ago
  My experience after a few years of OMAD fasting is that my body adapted really deeply. I don't get hungry (as long as I do eventually eat) and I have consistent energy levels throughout the day. If I know I'm about to do some long hike the next day (sometimes very long! 30+ miles) I try to eat extra the day before so I won't run out of energy the next day, which has also happened to me towards the end of a hike.
- iamacyborg 4y ago
  Generally if you're training it's helpful to train fasted, the idea being that you want your body to adapt to consuming fat for energy rather than relying on other fuel sources.
alwillis 4y ago
I highly recommend this episode of the Huberman Lab podcast about intermittent fasting from a Stanford professor: https://youtu.be/9tRohh0gErM https://youtu.be/9tRohh0gErM
- sumanmd 4y ago
  Thank you will check it out.
mhh__ 4y ago
Working from home has convinced me that a lot of western people don't really need more than one meal a day (or even one). Growing up sort of poor-ish, I have noticed that a lot of my eating habits are basically not far off Dickensian "Eat now, you might not have anything at all tomorrow" patterns.
- drieddust 4y ago
  An old Indian saying goes like this. Healthy eating and regular fasting is a big part of ancient Indian system still followed. Wordly people eats twice a day, Ascetics eats once a day, Children and invalids eats throughout the day.
  - sumanmd 4y ago
    Most of the ancient cultures, I do believe were fasting was a longer phenomenon, possibly days to weeks.
  - javert 4y ago
    I'm a normal person, which I think is morally better than being an ascetic, but I only eat once a day.
    - drieddust 4y ago
      What makes you think you have to leave for jungle to be an ascetic? You are an ascetic by all means if you have control over your senses. At least Hinduism defines it that way.
- sumanmd 4y ago
  Yes we are in a culture of nonstop eating. Once we understand the basic phenomenon of fasting and or caloric restriction, its easier to restrain from eating excess.
- Wohlf 4y ago
  Unfortunately we have to overcome both instinct, motivation, and willpower.
deleted 4y ago
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jlduan 4y ago
Very interesting. I alway thought the key of longevity is speaking Japanese.
- maximus-decimus 4y ago
  Weird, I thought the key to speaking Japanese was longevity.
gojuka 4y ago
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- sumanmd 4y ago
  Awesome. It does have lot of benefits especially reversing the metabolic disease.
g-unit33 4y ago
When I fasted I ended up gaining weight after a while. My assumption is that my body knew I wouldn’t eat for a while so it would absorb the food and not digest it as effectively so that I can have more fuel. What I do now is I randomly fast on random days and random times . It’s been more effective for me
- sumanmd 4y ago
  yes, fasting is unique to everyone. we have to understand our bodies and do the trial and error.
joshgroban 4y ago
Fasting brings quick results. Many on this site have trouble making sustained life changes because they spend a lot of time on the internet, and excessive internet use fuels impulsive habits. This leads people to choose health interventions that bring quick results that they can use to conclude a novel, controversial stance. When faced with RCTs, or waiting a decade to report an anecdote, or generation-long observational studies, or comparing with other more normal interventions, it's understandable why the broscience is attractive. We need positive results now.
- sumanmd 4y ago
  Fasting brings quick results but also long lasting.
- seer 4y ago
  While it does get you the fastest results if your goal is to gain wait, I personally wouldn’t put fasting into the same “impulsive” bucket. If anything it should be the other way around - fasting can be a way to teach yourself to tolerate/control your impulses. Anecdotally - the more I practice some form of it the more benefits I seem to derive. Just last month I noticed people dosing off in a long, tedious late afternoon meeting. For me though it just felt boring, but I could easily concentrate and stay focused. Since my only meal for the day is dinner, I’ve forced my body to generate glucose continuously throughout the day, so my brain has enough fuel, and I don’t need to rely on snack and chocolates. No sugar - no insulin spike - no afternoon sleepiness. I’ve stopped yo-yoing with my wait, as I’m pretty inconsistent with my exercise. It’s a lot simpler for me to force myself not to do something (eat) than to force myself to do something (train). Not to mention the whole longevity thing that is getting the rounds in the scientific community in recent years.
carbocation 4y ago
Worth being aware of the UCSF trial [1] that did not find that intermittent fasting (16 hour fast / 8 hours to eat) reduced weight. A bit concerningly, they did find that there was significantly reduced lean mass in the intermittent fasting group compared to the control group (a small but statistically significant effect). 1 = https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2771095?guestAccessKey=444bbcb2-7e13-4dc6-998f-5de5e27aa19e https://jamanetwork.com/journals/jamainternalmedicine/fullar...
- mrslave 4y ago
  I recall reading that this is true, but the narrow eating window is believed to contribute to ease of adherence. (No citations on hand, sorry.) My dieting successes have come from both a narrow eating window and lower carb (basically less sweet fruits, and non-root vegetables). Last time I adhered for 40 or so days I hit the wall hard (approx. -10 kg). Zero energy, and miserable. I wasn't sure if it was electrolytes or if I finally found the keto flu (seems a bit late though, and didn't pass in 3 days). So I abandoned ship and have since had no trouble putting 5 kg of fat back on my body. Time to restart!
- AA-BA-94-2A-56 4y ago
  This study by its own admission has no access to information on the amount of energy consumed by either group. It is possible to eat as many calories in one sitting as it is across the day; therefore, it is possible that people ate about the same calories/perhaps regulated by homeostasis.
  - iamacyborg 4y ago
    > therefore, it is possible that people ate about the same calories/perhaps regulated by homeostasis. Are you testing for the effects of fasting or calorie consumption?
xkfm 4y ago
I'm currently doing an eating window of about 2-3 hours, but I don't really track it. However, to maintain my weight, I've been doing 1-2 days of very low calories, similar to the PSMF diet from back in the day. In practice, I just eat 1.8g/kg bodyweight of protein and still take my daily supplements. I find not eating throughout the day helps me to maintain stable energy levels and focus. Also, on even on the vlc days I'm not any hungrier because I had a full meal the day before. No hunger pains or cravings at all. One of the strangest sensations is still pooping 2-3x the next day even though I haven't eaten anything. You quickly realize that all the food you ate takes longer to fully process than you thought. I usually eat after work and going to the gym. In order to make sure I can still exercise; I just make sure to have some electrolytes in the water I take to my gym and I'm usually fine. Sometimes it gets sketchy on intense days, but if I know it's going to be a hard day in the gym, all I need is about 30-50g of carbs and I'm fine. My diet still isn't very good. Typical American diet. However, I find it easy to eat high octane foods that used to put me on my ass literally or mentally if I've been "fasting". Fasting is my favorite way to maintain and lose weight. It's very braindead, time efficient, and cheap once you get used to it. After you become more aware of your bodies hunger sensations and all the habits you have wrapped around food, the biggest thing with "fasting" is making sure you get enough electrolytes. I've done a few pure water fasts up to a week in duration and a few 2-3 day dry fasts with one four day one. Pure water fasting I tend to be fine for about 4 days and then my energy/focus will start to drop. Dry fasting it happens in about two days. Technically it's not fasting with the electrolytes. But for weight loss, it doesn't really make a difference. It's interesting watching science tease out the benefits of very low calories versus very low calories and a restricted eating window. In a weight loss context, I don't think it matters that much really in terms of additional weight loss.
- sumanmd 4y ago
  Great. Fasting is easy way to be in shape and also build muscle.
  - geoduck14 4y ago
    I'm a Christian. One of the key points of fasting is to humble yourself; it is a way of saying "food is less important than my relationship with God".
robarr 4y ago
Adding a data point: Recent article on the New York Times about this study: https://www.nejm.org/doi/full/10.1056/NEJMoa2114833 https://www.nejm.org/doi/full/10.1056/NEJMoa2114833 https://www.nytimes.com/2022/04/20/health/time-restricted-diets.html https://www.nytimes.com/2022/04/20/health/time-restricted-di... The study refers only to restriction in search of weight loss. Edited to remove one word that may have been perceived as sarcastic.
aeternum 4y ago
Why aren't there any large-scale studies on this? It seems that even with all the meal tracking apps out there now, we would have an amazing data set on fasting. It's crazy that the best we have are either animal studies or some UCSF study of ~100 people for just 12 weeks. (Very low-power study)
cko 4y ago
Question on caloric restriction. I have read that it is the main reason that fasting (even intermittent) works. I heard mice that ate 40% fewer calories lived way longer or something like that. I'm a thin dude (6'3" and 165lbs). If I don't force myself to eat I will drop towards 155lbs, as has happened before. I eat in a 6-8 hour window daily but I aim for 2000-2500 calories. What would caloric restriction in this context look like?
- jdkoeck 4y ago
  Well, at this height, are you not calorie-restricted already?
  - urubu 4y ago
    Depends on the activity level. According to this calculator: https://www.calculator.net/bmr-calculator.html https://www.calculator.net/bmr-calculator.html his (assuming a dude) energy expenditure is: Basal metabolic rate: 1819 cal/day Sedentary (little or no exercise) 2,183 Exercise 1-3 times/week 2,501
    - watwut 4y ago
      If he is in the "little or no exercise" category, he should aim to get into "Exercise" category. Exercise (in reasonable amount) is healthy whether you loose weight or not. He should not be aiming for "basal metabolic rate".
  - cko 4y ago
    So does caloric restriction in general just mean maintaining a low-ish BMI?
    - 2muchcoffeeman 4y ago
      I think you should think about it as consuming less energy than your body needs everyday. This specific commenter could be considered too light for his frame. 165lbs is only 75kg. If anything, eat more and put on muscle.
imranq 4y ago
Most religions have some component of fasting, like Ramadan or Lent. Certainly there's value in doing more with less
- stjohnswarts 4y ago
  Those are for purely religious reasons though and have nothing to do with health concerns, so I'm not sure what you're getting at?
  - croon 4y ago
    While wary of noise levels (eg rules established to abuse power within the hierarchy), it's not unreasonable to assume some religious rules developed empirically over time. Not eating shellfish likely due to risks of disease, for example.
theagilecoder 4y ago
I was at 24% body fat and after trying 24 hours water fast 3 times a week for 2 weeks, I have come down to 19% losing 4 kgs in the process. After this I didnt fast for 2 weeks as I wanted to confirm it was not water weight and I am still at 19%. Also, post prandial insulin came down to 18 μU/mL from 28 μU/mL (2 hour mark Kraft test). I have tried cardio and calorie reduction before to reduce fat and have got decent results but fasting is so quick so it is now going to be my preferred way for cutting.
- sudhirj 4y ago
  Is a 24 hour fast the same as one specific meal a day? Like you have breakfasts on the days you're fasting?
  - kuhewa 4y ago
    Generally would be taken to mean you had a meal at night then go to sleep. then the following day eat nothing and go to sleep. Eat normally when you wake. Eating one meal a day even breakfast would be considered a 23-1 intermittent fasting schedule or something, but realistically you are in a fed postprandial state for several hours after the meal so there's some daylight between one meal a day and actual 24 hour fasts.
- sph 4y ago
  Sorry if I'm missing the point, but of course if you don't eat you lose weight pretty fast. I'm not a fan of CICO but when calories in = 0 and the average TDEE is around 2500 kcal, it's a pretty simple equation. The rule of thumb is 1 kg of body fat is equivalent to 7000 kcal of energy deficit.
  - tokamak-teapot 4y ago
    For those who aren’t well practised in shifting their body composition ‘at will’ - i.e. nearly everyone - CICO strategy is key when they are looking to reduce body fat. There are a few who claim, without any substantiation I can see, that CICO is not the main factor in losing fat, and I’m sure there will be some oddness around the edges which makes this at least not 100% black and white, but yes CICO itself is generally accepted as what all fat loss is driven from. So back to CICO strategy, because it’s that which nearly everyone struggles with, not CICO in and of itself. Choosing a strategy that is comfortable enough for a person to sustain is key to long term maintenance of desired body fat level. Some are happy to just eat at a maintenance level through three meals a day, but for many this just makes them miserable and they creep up the calories over time. Fasting is, for many, a much easier strategy to sustain. Often there is only a small period of hunger in a short fast, but this can even disappear with practice. Fasting can feel great during the fast, and make you feel good when you’re not fasting. CICO is under your control and you’re it even finding it hard. This is why fasting is a great choice for many.
mzs 4y ago
Few years back my doctor was concerned about my blood pressure and recommended I lose weight. I asked how and he after the expected recommendations about eating healthier and exercising he added, "but whatever you do, don't fast." I asked why and he said it doesn't really work better long-term but increases the risk of other health problems especially gall-stones. A year later I weighed 10% less and my blood pressure was normal again. I ate less salt, fat, and sugar plus took-up soccer again. Years later I'm still not chonky again.
- jwilber 4y ago
  Are you saying you did fast or did not fast?
  - mzs 4y ago
    I didn't fast, I consumed less fat sugar and salt and played soccer but ate at the normal times.
Bessie69 4y ago
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Madmallard 4y ago
Fasting can work well for weight loss but it must be done with care. https://www.youtube.com/watch?v=tWlvWYGztYk https://www.youtube.com/watch?v=tWlvWYGztYk Dr Bernard has some to say on this matter, after his case of the woman who experienced refeeding syndrome and had to be hospitalized.
- deleted 4y ago
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irthomasthomas 4y ago
Since lockdown I have been consistently eating 1 meal a day, with occasional 2 day fasts and rarely 3-4 day fasts. It is so natural to me now that on my last stay in London I got 2 days in to the trip when I suddenly realised I'm in London, surrounded by amazing food I can't get at home, I should eat more and enjoy. So I gorged on Indian, Jamaican, Vietnamese, I was surprised how much I could put away, so much walking had stimulated my appetite. On the science of fasting. It was Ancel Keys whose research, in the 60s, led to the invention of the Mediterranean diet as a way of reducing obesity and heart disease in America. Keys work provided the intellectual justification for the McGovern senate committee, in 1977, to propose radical changes to diet and to government policy. The top-down approach to the national diet led the government to adopt the Low Fat Diet as policy, e.g. the https://en.m.wikipedia.org/wiki/National_School_Lunch_Act https://en.m.wikipedia.org/wiki/National_School_Lunch_Act Can you spot 1977 on this obesity chart? https://www.ncbi.nlm.nih.gov/books/NBK19623/figure/chartbook.f7/?report=objectonly https://www.ncbi.nlm.nih.gov/books/NBK19623/figure/chartbook... Since Keys death, dissenting voices have gotten louder: "In the December 2004 issue of your journal, in his column, Geoffrey Cannon referred to Ancel Keys’ Seven Countries Study and the fact that Keys and his colleagues seemed to have ignored the possibility that Greek Orthodox Christian fasting practices could have influenced the dietary habits of male Cretans in the 1960s. For this reason, we had a personal communication with Professor Christos Aravanis, who was responsible for carrying out and following up the Seven Countries Study in Greece. Professor Aravanis conﬁrmed that, in the 1960s, 60% of the study participants were fasting during the 40 days of Lent, and strictly followed all fasting periods of the church according to the Greek Orthodox Church dietary doctrines. These mainly prescribe the periodic abstention from meat, ﬁsh, dairy products, eggs and cheese, as well as abstention from olive oil consumption on certain Wednesdays and Fridays. However, it is indeed the case that this was not noted in the study, and no attempt was made to differentiate between fasters and non-fasters. In our view this was a markable and troublesome omission. The Greek Orthodox Church prescribes almost 180 days of fasting per year. It is unknown to what extent the Cretans who were the original subjects of the Seven Countries Study and who fasted during Lent also followed the precepts of their Church throughout the year, and thus on how many days in total and to what extent the Cretan participants of the Seven Countries Study fasted" https://www.researchgate.net/publication/7530689_The_Seven_Countries_Study_in_Crete_Olive_oil_Mediterranean_diet_or_fasting https://www.researchgate.net/publication/7530689_The_Seven_C... The fatal blow to Keys' lipid hypothesis was dealt in 2016 after data from another Keys' experiment was re-examined. "Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment" concludes: Results – The intervention group had significant reduction in serum cholesterol compared with controls (mean change from baseline −13.8% v −1.0%; P<0.001). Kaplan Meier graphs showed no mortality benefit for the intervention group in the full randomized cohort or for any prespecified subgroup. There was a 22% higher risk of death for each 30 mg/dL (0.78 mmol/L) reduction in serum cholesterol in covariate adjusted Cox regression models (hazard ratio 1.22, 95% confidence interval 1.14 to 1.32; P<0.001). There was no evidence of benefit in the intervention group for coronary atherosclerosis or myocardial infarcts. Systematic review identified five randomized controlled trials for inclusion (n=10 808). In meta-analyses, these cholesterol lowering interventions showed no evidence of benefit on mortality from coronary heart disease (1.13, 0.83 to 1.54) or all cause mortality (1.07, 0.90 to 1.27). Conclusions – Available evidence from randomized controlled trials shows that replacement of saturated fat in the diet with linoleic acid effectively lowers serum cholesterol but does not support the hypothesis that this translates to a lower risk of death from coronary heart disease or all causes. Findings from the Minnesota Coronary Experiment add to growing evidence that incomplete publication has contributed to overestimation of the benefits of replacing saturated fat with vegetable oils rich in linoleic acid." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4836695/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4836695/
mikevm 4y ago
Meh, once again with this fasting fad. There's no evidence at this point that fasting is superior to continuous caloric restriction. There's also no evidence that any of the touted health benefits of intermittent-fasting are special to this method of weight loss -- any of them can be achieved by a regular caloric restriction diets. Most of the health benefits are due to weight loss / fat loss. Longer fasts (over 16 hours, IIRC) are also catabolic to muscle mass, so they're not even recommended for people who have optimal training plans. One meal per day is also not enough as only a certain amount of the consumed protein is going to be used for muscle protein synthesis so it's optimal to spread the consumption across multiple meals. If you lift (and you should!), you should strive for 1.4-1.8g/kg of protein per day, try to hit the leucine threshold per meal (even though this is just a hypothesis!), and use calorie cycling to consume more of the protein around the workout window (anabolic window -- it's not been debunked!!!). Try not to go below 50g fat per day, and do whatever you please as far as carbs go :). I'm personally not a fan of keto as it's too restrictive.
motbus3 4y ago
most of us will do less than 3 meals in the next 60y possibly less than 14 per week but not for health related reasons
sumanmd 4y ago
Great. Thank you for your awesome comments.
boatsie 4y ago
What’s so particularly frustrating is that despite record unchecked obesity, we are encouraging children to eat more than ever. In infancy, we always have bottle or breast ready where they cry. In toddlerhood, most activities and all preschools include “snack times”. My kids elementary school has 2 snacks plus lunch plus a snack for after school. Then if sports they are encouraged to have a snack before or after. Add in breakfast and dinner and they are eating 7-9 times a day! Additionally, the vast majority of these “snacks” require they be non-perishable which usually means mostly carbs and fat. I don’t understand why there is this constant emphasis on eating when it seems clear we eat entirely way too much.
paulpauper 4y ago
everyone is looking for a fix to weight gain, not even a quick fix, and various ideas and diets keep have been floated, much with limited to no success. There is no science behind fasting .If there were a science it would be effective and reproducible.

221 points by sumanmd 4y ago

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

deleted 4y ago
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mensetmanusman 4y ago

Black coffee and water from 5 am to 6 pm, eat from 6-9 pm works for me. Meals definitely taste better after that window :) I find I sometimes have like two dinners at 6 and 8 which is interesting…

Dig1t 4y ago
Very interesting, do you know the total calories you generally eat during that window?
- sumanmd 4y ago
  Less than 500 - 800 cal and no carbs for 2 days.
siavosh 4y ago
I did this for two years, lost a fair bit of weight. But the gorging at dinner time really messed up my cholesterol levels. So just an advice that one's weight isn't the only metric of health, if you do any diet change consult your doctor, and confirm health across multiple dimensions (blood tests etc). Today, I do a heart healthy diet, and try to fast from 8PM-12PM (eat between 12PM-8PM). This helps me not eat/snack unhealthily in a condensed period of time.
- kmeraz 4y ago
  Curious, what was it about gorging at dinner time that messed up your cholesterol levels? Was it because you'd gorge on foods high in cholesterol, or was there another mechanism at play?
  - itchyouch 4y ago
    My doctor gave me A cursory explanation so I can’t vouch for my limited understanding. That said, cholesterol is essential for the production of bile which breaks down foods. Late night foods probably equates to excess cholesterol released to break down said foods and higher cholesterol levels. We probably want to have periods of fasting in order to not produce excess cholesterol.
    - melissalobos 4y ago
      > cholesterol is essential for the production of bile which breaks down foods So maybe the person fasting had higher cholesterol levels due to his body needing more bile immediately to breakdown a larger amount of food at once? I am very much not a doctor or at all educated in these topics.
    - sumanmd 4y ago
      There are multiple mechanisms as play when we discuss about cholesterol. I will do an article discussing about this in the future.
  - siavosh 4y ago
    I probably implied more causation than I meant. I know nothing about fasting causing my high cholesterol directly. What I do know is I thought my weight not going up liberated me into eating whatever my heart desired in my 4-5 hour feeding window. This feast/famine mentality did me no good given my personality type and I probably ended up eating a lot more food and snacks than I would of otherwise.
- sumanmd 4y ago
  Great. Congratulations on you IF journey.
jjtheblunt 4y ago
Do you not burn up your stomach from the acidity of that diet?
- jstx1 4y ago
  Do you mean because of the coffee? I drink several cups of strong black coffee on an empty stomach every day and I've never had any problems whatsoever.
  - jjtheblunt 4y ago
    That's awesome, and, yes, that's what i wondered; personally i couldn't, presumably different from person to person. Thanks.
    - Melatonic 4y ago
      It varies a ton per person - I know that I often, for example, end up with the opposite of acid reflux (essentially my stomach is too basic). I would have similar symptoms and take an antacid and it would make it immediately WORSE. Not sure if this is why but I am also one of those people that can eat super acidic foods all day no problem - I can drink black coffee and follow that up with a bunch of citrus and feel great.
      - jjtheblunt 4y ago
        oh wow, i'm the opposite: non diluted coffee and i burn, even got scoped and showed gastritis...i evidently am at the acidic end, or just not healed enough, in a vicious burn cycle perhaps...
        Melatonic 4y ago
        The HN news hoardes will probably be here soon to chastise me for even remotely giving health advice over the internet but when I had an ulcer I found out that in Japan doctors will actually prescribe powdered Glutamine (its just an amino acid - common building block of protein - so pretty damn safe) for ulcers and many things that involve the lining of the GI tract. Apparently the walls can directly use glutamine to help repair themselves. Seems to help me a lot and I just regularly started taking small amounts of it daily since I sometimes love eating an exorbitant amount of spicy food and that can be pretty harsh on your insides.
motohagiography 4y ago
Am on same one meal a day scheme (espressos in morning, nothing but dinner) for a year and love it. However, it's literally just replacing 2/3 meals out of my day with multiple servings of a highly addictive stimulant. Obviously I'm fine, but I am sure our descendents will look back on coffee as some kind of traditional folk-meth.
- sumanmd 4y ago
  Great!
zemvpferreira 4y ago
Worth it to point out that coffee (and anything you ingest really, including water) will activate bits of your metabolism and having it will not be equivalent to a complete fast for certain purposes. Not that you're wrong having it, just something to realize. Will almost certainly have a negligible or even positive effect on weight loss.
- robbiep 4y ago
  Generally (and certainly most of the recent fasting trends) fasting is referred to as no more than 500 kcal intake, which is of course different to a ‘true’ definition which would be nothing, except maybe water
  - gretch 4y ago
    500 Calories!? That’s so much. 1 large boiled egg is 80 Calories. So like eat 5 or 6 eggs and you haven’t broken your fast??
    - sumanmd 4y ago
      500 cal doesn't constitute for water only fasts.
    - maccard 4y ago
      500 calories is my breakfast most days. that's not a fast!
  - sumanmd 4y ago
    Fasting definition keeps changing. There is water only and then there is water only and less than 500 Cal.
  - ycombinete 4y ago
    I guess that depends. 500 calories is 1/3 of my wife’s maintenance calories.
- sumanmd 4y ago
sumanmd 4y ago
Interesting, whatever works !
qqqwerty 4y ago
Just as a word of warning, acidic coffee and late night eating are two habits heavily associated with acid reflux/GERD. I had similar habits, was relatively healthy, and rarely if ever suffered from heart burn. But about a year ago, seemingly overnight, I came down with severe acid reflux. I am still managing symptoms to this day. Not saying it will happen to you, but just raising awareness that human health is a fickle thing and it can take a turn for the worse quickly, often with little to no warning.
- mensetmanusman 4y ago
  Good point, I do eat a lot of yogurt and salad and stay away from super greasy foods to prevent reflux :)
seer 4y ago
I’ve found eating once a day to be quite tough on the finances. We often eat out, so instead of ordering just dinner, I get all my calories from that one meal, which ends up being quite expensive. So at least for me fasting turned out more expensive :-D On the plus side, I like to try different dishes, as I’m a very curious eater, and now I don’t have to feel guilty when I do.
- mensetmanusman 4y ago
  You should pregame with a pint of greek yogurt!

hobo_mark 4y ago

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

melissalobos 4y ago
> Where is the limit? You lose roughly ~0.75 lbs of body fat at normal fasting levels assuming a reasonably active regular sized person. So how ever many days worth of body fat you would like to gain and lose regularly. You would have to eat back the same amount and probably wouldn't want to gorge yourself too much. A reasonable practical limit might be 5 days. All of that assumes that you want to maintain a set weight. So the real limit is how much you want to eat in a single sitting. Take those calories and average them across as many days as needed to maintain weight.
- angrais 4y ago
  Can you explain the .75lbs number you provided? How often do you anticipate a person to lose that much? Care to provide literature for your claims?
  - melissalobos 4y ago
    1lb of body fat is ~3500 calories. An average person doing average things burns around 2000 calories. You can easily put in your own numbers and get your own results. Just calculate your TDEE(total daily energy expenditure) and look up how many calories in a pound of fat to whatever tolerance you want.
  - db65edfc7996 4y ago
    Not the GP, but a pound of fat = 3500 kCal. If you use the standard 2000 kCal / day basis, that gets you to .57 lbs fat loss per day. Also, the 450 pound (204 kg) man who did not eat for an entire year [0] lost 0.72 pounds / day. [0] https://pmj.bmj.com/content/49/569/203 https://pmj.bmj.com/content/49/569/203

c54 4y ago

I've been long exposed to the standard tech-circles common knowledge about intermittent fasting (IF), the benefits of fasting, basic gym science about calorie restriction, and so on. I thought a lot of this stuff was pretty well confirmed by science as well as various fasting-oriented traditions around the world. Fast one day a week, live longer. Work IF into your eating schedule, increase your productivity and give your body time to 'clean up' your system. But I was surprised to recently realize how novel a lot of fasting research is, and how unconfirmed a lot of the benefits are. Even the wikipedia page for fasting doesn't have as much as I'd really like to see. It's nice to see posts like this one, but even this doubles down on "there are studies in progress" without any convincing completed studies. Review studies such as this[0] one basically confirm in so many words that "additional trials are needed" and while IF can help you lose weight "whether IF itself affects cancer-related metabolic and molecular pathways remains unanswered" It's curiously similar to woo-woo or religious habits and self-help advice: similar in being fringe from the perspective of scientific medicine. But the same groups who I'd expect to be pro-science (for example more likely to get vaccinated) are often mixed up in fasting stuff which isn't (yet) confirmed. I suppose it's not too unheard of to see tech circles overlap with fringe medicine. Check out r/nootropics for instance. Now, I've experimented with nootropics and various supplements. I don't use the term 'fringe' as a haughty outsider. I'm quite willing to consider that it's "not yet confirmed" protoscience, and that this is different from falsified or counter-indicated "remedies" and bits of fringe medicine, things like homeopathy. But it's curious nonetheless. [0] https://acsjournals.onlinelibrary.wiley.com/doi/10.3322/caac.21694 https://acsjournals.onlinelibrary.wiley.com/doi/10.3322/caac...

tashoecraft 4y ago
I think a large part of the problem is we may never have big studies for this. It’s very difficult to do human trials, you can’t just lock people up and restrict their calories for years on end.
- mountainboy 4y ago
  the bigger question is: who would pay for such studies? big pharma? government lobbied by big pharma? universities given grants from government lobbied by big pharma? actually though, the soviets did do serious research into the science/benefits of fasting. Too bad it never really made it to the west. Watch the video: "The Science of Fasting" for an overview.

taytus 4y ago

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

photochemsyn 4y ago

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

BlargMcLarg 4y ago
Science actually suggests fasting increases metabolism, or at least keeps it stable, unlike general caloric restriction.
giraffe_lady 4y ago
Sounds really unpleasant honestly. I pretty frequently eat only one insufficient meal/day or fully fast for non-health reasons and there's no getting around the fact that exercise on those days fucking sucks. If there's any benefit I can't see it being worth it except in extreme cases. Particularly endurance exercise without calories afterwards is one of the worst things you can do to your day.
tibbar 4y ago
My experience after a few years of OMAD fasting is that my body adapted really deeply. I don't get hungry (as long as I do eventually eat) and I have consistent energy levels throughout the day. If I know I'm about to do some long hike the next day (sometimes very long! 30+ miles) I try to eat extra the day before so I won't run out of energy the next day, which has also happened to me towards the end of a hike.
iamacyborg 4y ago
Generally if you're training it's helpful to train fasted, the idea being that you want your body to adapt to consuming fat for energy rather than relying on other fuel sources.

alwillis 4y ago

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

sumanmd 4y ago
Thank you will check it out.

mhh__ 4y ago

Working from home has convinced me that a lot of western people don't really need more than one meal a day (or even one). Growing up sort of poor-ish, I have noticed that a lot of my eating habits are basically not far off Dickensian "Eat now, you might not have anything at all tomorrow" patterns.

drieddust 4y ago
An old Indian saying goes like this. Healthy eating and regular fasting is a big part of ancient Indian system still followed. Wordly people eats twice a day, Ascetics eats once a day, Children and invalids eats throughout the day.
- sumanmd 4y ago
  Most of the ancient cultures, I do believe were fasting was a longer phenomenon, possibly days to weeks.
- javert 4y ago
  I'm a normal person, which I think is morally better than being an ascetic, but I only eat once a day.
  - drieddust 4y ago
    What makes you think you have to leave for jungle to be an ascetic? You are an ascetic by all means if you have control over your senses. At least Hinduism defines it that way.
sumanmd 4y ago
Yes we are in a culture of nonstop eating. Once we understand the basic phenomenon of fasting and or caloric restriction, its easier to restrain from eating excess.
Wohlf 4y ago
Unfortunately we have to overcome both instinct, motivation, and willpower.

deleted 4y ago

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jlduan 4y ago

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

maximus-decimus 4y ago
Weird, I thought the key to speaking Japanese was longevity.

gojuka 4y ago

[dead]

sumanmd 4y ago
Awesome. It does have lot of benefits especially reversing the metabolic disease.

g-unit33 4y ago

When I fasted I ended up gaining weight after a while. My assumption is that my body knew I wouldn’t eat for a while so it would absorb the food and not digest it as effectively so that I can have more fuel. What I do now is I randomly fast on random days and random times . It’s been more effective for me

sumanmd 4y ago
yes, fasting is unique to everyone. we have to understand our bodies and do the trial and error.

joshgroban 4y ago

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

sumanmd 4y ago
Fasting brings quick results but also long lasting.
seer 4y ago
While it does get you the fastest results if your goal is to gain wait, I personally wouldn’t put fasting into the same “impulsive” bucket. If anything it should be the other way around - fasting can be a way to teach yourself to tolerate/control your impulses. Anecdotally - the more I practice some form of it the more benefits I seem to derive. Just last month I noticed people dosing off in a long, tedious late afternoon meeting. For me though it just felt boring, but I could easily concentrate and stay focused. Since my only meal for the day is dinner, I’ve forced my body to generate glucose continuously throughout the day, so my brain has enough fuel, and I don’t need to rely on snack and chocolates. No sugar - no insulin spike - no afternoon sleepiness. I’ve stopped yo-yoing with my wait, as I’m pretty inconsistent with my exercise. It’s a lot simpler for me to force myself not to do something (eat) than to force myself to do something (train). Not to mention the whole longevity thing that is getting the rounds in the scientific community in recent years.

carbocation 4y ago

Worth being aware of the UCSF trial [1] that did not find that intermittent fasting (16 hour fast / 8 hours to eat) reduced weight. A bit concerningly, they did find that there was significantly reduced lean mass in the intermittent fasting group compared to the control group (a small but statistically significant effect). 1 = https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2771095?guestAccessKey=444bbcb2-7e13-4dc6-998f-5de5e27aa19e https://jamanetwork.com/journals/jamainternalmedicine/fullar...

mrslave 4y ago
I recall reading that this is true, but the narrow eating window is believed to contribute to ease of adherence. (No citations on hand, sorry.) My dieting successes have come from both a narrow eating window and lower carb (basically less sweet fruits, and non-root vegetables). Last time I adhered for 40 or so days I hit the wall hard (approx. -10 kg). Zero energy, and miserable. I wasn't sure if it was electrolytes or if I finally found the keto flu (seems a bit late though, and didn't pass in 3 days). So I abandoned ship and have since had no trouble putting 5 kg of fat back on my body. Time to restart!
AA-BA-94-2A-56 4y ago
This study by its own admission has no access to information on the amount of energy consumed by either group. It is possible to eat as many calories in one sitting as it is across the day; therefore, it is possible that people ate about the same calories/perhaps regulated by homeostasis.
- iamacyborg 4y ago
  > therefore, it is possible that people ate about the same calories/perhaps regulated by homeostasis. Are you testing for the effects of fasting or calorie consumption?

xkfm 4y ago

I'm currently doing an eating window of about 2-3 hours, but I don't really track it. However, to maintain my weight, I've been doing 1-2 days of very low calories, similar to the PSMF diet from back in the day. In practice, I just eat 1.8g/kg bodyweight of protein and still take my daily supplements. I find not eating throughout the day helps me to maintain stable energy levels and focus. Also, on even on the vlc days I'm not any hungrier because I had a full meal the day before. No hunger pains or cravings at all. One of the strangest sensations is still pooping 2-3x the next day even though I haven't eaten anything. You quickly realize that all the food you ate takes longer to fully process than you thought. I usually eat after work and going to the gym. In order to make sure I can still exercise; I just make sure to have some electrolytes in the water I take to my gym and I'm usually fine. Sometimes it gets sketchy on intense days, but if I know it's going to be a hard day in the gym, all I need is about 30-50g of carbs and I'm fine. My diet still isn't very good. Typical American diet. However, I find it easy to eat high octane foods that used to put me on my ass literally or mentally if I've been "fasting". Fasting is my favorite way to maintain and lose weight. It's very braindead, time efficient, and cheap once you get used to it. After you become more aware of your bodies hunger sensations and all the habits you have wrapped around food, the biggest thing with "fasting" is making sure you get enough electrolytes. I've done a few pure water fasts up to a week in duration and a few 2-3 day dry fasts with one four day one. Pure water fasting I tend to be fine for about 4 days and then my energy/focus will start to drop. Dry fasting it happens in about two days. Technically it's not fasting with the electrolytes. But for weight loss, it doesn't really make a difference. It's interesting watching science tease out the benefits of very low calories versus very low calories and a restricted eating window. In a weight loss context, I don't think it matters that much really in terms of additional weight loss.

sumanmd 4y ago
Great. Fasting is easy way to be in shape and also build muscle.
- geoduck14 4y ago
  I'm a Christian. One of the key points of fasting is to humble yourself; it is a way of saying "food is less important than my relationship with God".

robarr 4y ago

Adding a data point: Recent article on the New York Times about this study: https://www.nejm.org/doi/full/10.1056/NEJMoa2114833 https://www.nejm.org/doi/full/10.1056/NEJMoa2114833 https://www.nytimes.com/2022/04/20/health/time-restricted-diets.html https://www.nytimes.com/2022/04/20/health/time-restricted-di... The study refers only to restriction in search of weight loss. Edited to remove one word that may have been perceived as sarcastic.

aeternum 4y ago

Why aren't there any large-scale studies on this? It seems that even with all the meal tracking apps out there now, we would have an amazing data set on fasting. It's crazy that the best we have are either animal studies or some UCSF study of ~100 people for just 12 weeks. (Very low-power study)

cko 4y ago

Question on caloric restriction. I have read that it is the main reason that fasting (even intermittent) works. I heard mice that ate 40% fewer calories lived way longer or something like that. I'm a thin dude (6'3" and 165lbs). If I don't force myself to eat I will drop towards 155lbs, as has happened before. I eat in a 6-8 hour window daily but I aim for 2000-2500 calories. What would caloric restriction in this context look like?

jdkoeck 4y ago
Well, at this height, are you not calorie-restricted already?
- urubu 4y ago
  Depends on the activity level. According to this calculator: https://www.calculator.net/bmr-calculator.html https://www.calculator.net/bmr-calculator.html his (assuming a dude) energy expenditure is: Basal metabolic rate: 1819 cal/day Sedentary (little or no exercise) 2,183 Exercise 1-3 times/week 2,501
  - watwut 4y ago
    If he is in the "little or no exercise" category, he should aim to get into "Exercise" category. Exercise (in reasonable amount) is healthy whether you loose weight or not. He should not be aiming for "basal metabolic rate".
- cko 4y ago
  So does caloric restriction in general just mean maintaining a low-ish BMI?
  - 2muchcoffeeman 4y ago
    I think you should think about it as consuming less energy than your body needs everyday. This specific commenter could be considered too light for his frame. 165lbs is only 75kg. If anything, eat more and put on muscle.

imranq 4y ago

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

stjohnswarts 4y ago
Those are for purely religious reasons though and have nothing to do with health concerns, so I'm not sure what you're getting at?
- croon 4y ago
  While wary of noise levels (eg rules established to abuse power within the hierarchy), it's not unreasonable to assume some religious rules developed empirically over time. Not eating shellfish likely due to risks of disease, for example.

theagilecoder 4y ago

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

sudhirj 4y ago
Is a 24 hour fast the same as one specific meal a day? Like you have breakfasts on the days you're fasting?
- kuhewa 4y ago
  Generally would be taken to mean you had a meal at night then go to sleep. then the following day eat nothing and go to sleep. Eat normally when you wake. Eating one meal a day even breakfast would be considered a 23-1 intermittent fasting schedule or something, but realistically you are in a fed postprandial state for several hours after the meal so there's some daylight between one meal a day and actual 24 hour fasts.
sph 4y ago
Sorry if I'm missing the point, but of course if you don't eat you lose weight pretty fast. I'm not a fan of CICO but when calories in = 0 and the average TDEE is around 2500 kcal, it's a pretty simple equation. The rule of thumb is 1 kg of body fat is equivalent to 7000 kcal of energy deficit.
- tokamak-teapot 4y ago
  For those who aren’t well practised in shifting their body composition ‘at will’ - i.e. nearly everyone - CICO strategy is key when they are looking to reduce body fat. There are a few who claim, without any substantiation I can see, that CICO is not the main factor in losing fat, and I’m sure there will be some oddness around the edges which makes this at least not 100% black and white, but yes CICO itself is generally accepted as what all fat loss is driven from. So back to CICO strategy, because it’s that which nearly everyone struggles with, not CICO in and of itself. Choosing a strategy that is comfortable enough for a person to sustain is key to long term maintenance of desired body fat level. Some are happy to just eat at a maintenance level through three meals a day, but for many this just makes them miserable and they creep up the calories over time. Fasting is, for many, a much easier strategy to sustain. Often there is only a small period of hunger in a short fast, but this can even disappear with practice. Fasting can feel great during the fast, and make you feel good when you’re not fasting. CICO is under your control and you’re it even finding it hard. This is why fasting is a great choice for many.

mzs 4y ago

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

jwilber 4y ago
Are you saying you did fast or did not fast?
- mzs 4y ago
  I didn't fast, I consumed less fat sugar and salt and played soccer but ate at the normal times.

Bessie69 4y ago

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Madmallard 4y ago

Fasting can work well for weight loss but it must be done with care. https://www.youtube.com/watch?v=tWlvWYGztYk https://www.youtube.com/watch?v=tWlvWYGztYk Dr Bernard has some to say on this matter, after his case of the woman who experienced refeeding syndrome and had to be hospitalized.

deleted 4y ago
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irthomasthomas 4y ago

Since lockdown I have been consistently eating 1 meal a day, with occasional 2 day fasts and rarely 3-4 day fasts. It is so natural to me now that on my last stay in London I got 2 days in to the trip when I suddenly realised I'm in London, surrounded by amazing food I can't get at home, I should eat more and enjoy. So I gorged on Indian, Jamaican, Vietnamese, I was surprised how much I could put away, so much walking had stimulated my appetite. On the science of fasting. It was Ancel Keys whose research, in the 60s, led to the invention of the Mediterranean diet as a way of reducing obesity and heart disease in America. Keys work provided the intellectual justification for the McGovern senate committee, in 1977, to propose radical changes to diet and to government policy. The top-down approach to the national diet led the government to adopt the Low Fat Diet as policy, e.g. the https://en.m.wikipedia.org/wiki/National_School_Lunch_Act https://en.m.wikipedia.org/wiki/National_School_Lunch_Act Can you spot 1977 on this obesity chart? https://www.ncbi.nlm.nih.gov/books/NBK19623/figure/chartbook.f7/?report=objectonly https://www.ncbi.nlm.nih.gov/books/NBK19623/figure/chartbook... Since Keys death, dissenting voices have gotten louder: "In the December 2004 issue of your journal, in his column, Geoffrey Cannon referred to Ancel Keys’ Seven Countries Study and the fact that Keys and his colleagues seemed to have ignored the possibility that Greek Orthodox Christian fasting practices could have influenced the dietary habits of male Cretans in the 1960s. For this reason, we had a personal communication with Professor Christos Aravanis, who was responsible for carrying out and following up the Seven Countries Study in Greece. Professor Aravanis conﬁrmed that, in the 1960s, 60% of the study participants were fasting during the 40 days of Lent, and strictly followed all fasting periods of the church according to the Greek Orthodox Church dietary doctrines. These mainly prescribe the periodic abstention from meat, ﬁsh, dairy products, eggs and cheese, as well as abstention from olive oil consumption on certain Wednesdays and Fridays. However, it is indeed the case that this was not noted in the study, and no attempt was made to differentiate between fasters and non-fasters. In our view this was a markable and troublesome omission. The Greek Orthodox Church prescribes almost 180 days of fasting per year. It is unknown to what extent the Cretans who were the original subjects of the Seven Countries Study and who fasted during Lent also followed the precepts of their Church throughout the year, and thus on how many days in total and to what extent the Cretan participants of the Seven Countries Study fasted" https://www.researchgate.net/publication/7530689_The_Seven_Countries_Study_in_Crete_Olive_oil_Mediterranean_diet_or_fasting https://www.researchgate.net/publication/7530689_The_Seven_C... The fatal blow to Keys' lipid hypothesis was dealt in 2016 after data from another Keys' experiment was re-examined. "Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment" concludes: Results – The intervention group had significant reduction in serum cholesterol compared with controls (mean change from baseline −13.8% v −1.0%; P<0.001). Kaplan Meier graphs showed no mortality benefit for the intervention group in the full randomized cohort or for any prespecified subgroup. There was a 22% higher risk of death for each 30 mg/dL (0.78 mmol/L) reduction in serum cholesterol in covariate adjusted Cox regression models (hazard ratio 1.22, 95% confidence interval 1.14 to 1.32; P<0.001). There was no evidence of benefit in the intervention group for coronary atherosclerosis or myocardial infarcts. Systematic review identified five randomized controlled trials for inclusion (n=10 808). In meta-analyses, these cholesterol lowering interventions showed no evidence of benefit on mortality from coronary heart disease (1.13, 0.83 to 1.54) or all cause mortality (1.07, 0.90 to 1.27). Conclusions – Available evidence from randomized controlled trials shows that replacement of saturated fat in the diet with linoleic acid effectively lowers serum cholesterol but does not support the hypothesis that this translates to a lower risk of death from coronary heart disease or all causes. Findings from the Minnesota Coronary Experiment add to growing evidence that incomplete publication has contributed to overestimation of the benefits of replacing saturated fat with vegetable oils rich in linoleic acid." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4836695/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4836695/

mikevm 4y ago

Meh, once again with this fasting fad. There's no evidence at this point that fasting is superior to continuous caloric restriction. There's also no evidence that any of the touted health benefits of intermittent-fasting are special to this method of weight loss -- any of them can be achieved by a regular caloric restriction diets. Most of the health benefits are due to weight loss / fat loss. Longer fasts (over 16 hours, IIRC) are also catabolic to muscle mass, so they're not even recommended for people who have optimal training plans. One meal per day is also not enough as only a certain amount of the consumed protein is going to be used for muscle protein synthesis so it's optimal to spread the consumption across multiple meals. If you lift (and you should!), you should strive for 1.4-1.8g/kg of protein per day, try to hit the leucine threshold per meal (even though this is just a hypothesis!), and use calorie cycling to consume more of the protein around the workout window (anabolic window -- it's not been debunked!!!). Try not to go below 50g fat per day, and do whatever you please as far as carbs go :). I'm personally not a fan of keto as it's too restrictive.

motbus3 4y ago

most of us will do less than 3 meals in the next 60y possibly less than 14 per week but not for health related reasons

sumanmd 4y ago

Great. Thank you for your awesome comments.

boatsie 4y ago

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

paulpauper 4y ago

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