9 ms·

A Guide to Intermittent Fasting

192 points by hunglee2 9y ago

wdewind 9y ago
Overall the body is pretty good at nutrient partitioning and maintaining a caloric balance. There may be small statistically different outcomes for practicing stuff like IF, but there aren't clinically different outcomes outside of using IF to maintain compliance to a diet. If IF helps you maintain your ability to comply to the diet you want, great, but there's absolutely no evidence for it being superior than the same diet spread over the day, and there a few ways in which it's probably suboptimal, like building muscle (although again not hugely so, so compliance probably trumps the small advantage you get).
- jraby3 9y ago
  What about in controlling insulin resistance? I thought the data was pretty strong in favor of IF helping significantly.
  - wdewind 9y ago
    It's not. The same amount of glycemic load consumed all at once or over time throughout the day will not have a significant effect on insulin resistance. Not being able to eat as much because you are constrained to an 8 hour window will cause your overall glycemic load to go down.
bykovich2 9y ago
"Calorie restriction is proven to help you live a longer life." Flatly untrue. The article linked to "in proof" is about primate studies that suggest -- perhaps even strongly suggest -- that caloric restriction can slow the process of aging. This does not, however, rise to the level of proof, and certainly does not provide conclusive indication of what caloric restricters can expect more generally. The author is apparently willing to make this grandiose claim to a susceptible audience with nary a word about its limitations, which should set our alarm bells ringing. If you want to calorically restrict, do it because you've thought long and hard about the consequences of a truly significant choice -- not because it's a tech industry fad.
- HorizonXP 9y ago
  I think the phenomenon is poorly understood and studied, but it's likely not the calorie restriction itself, like you claim. Apparently it has to do with autophagy (https://en.wikipedia.org/wiki/Autophagy https://en.wikipedia.org/wiki/Autophagy), which your body seems to enter when you restrict calories. IF apparently stimulates your body to perform autophagy due to the fact that you're timing your meals. TBH, I still need to do my own research to see how much of this is real vs. pseudoscience, but I've noticed an improvement to my health. Whether that's placebo effect or not, remains to be seen.
  - allover 9y ago
    Well GPP is just saying that 'calorie restriction' is not proven to 'help you live a longer life', irrespective of the IF context. As for IF, as you say, it is basically not proven to do anything (no 'phenomenon' at all). Simplest and most logical reason for success is because it helps people stick to their diet, by arbitrarily restricting the window of eating. Opinion I read on r/leangains is that some people find it easier to e.g. just eat two 600-800 calorie meals within their IF window, rather than sticking to a diet that involves 3-4 smaller ~300-400 calorie meals, spread out through the day, none of which feel 'satisfying'.
- nxsynonym 9y ago
  I agree, and this can be applied to every single diet fab that's been talked/tweeted/click-baited about in the past 10 years. I do IF, but that's because if I try to eat anything within 3 or 4 hours of waking up I feel nauseous and sleepy. I also find it easier to manage caloric intake by limiting my "feeding window" to 8 or 10 hours. There are also some fringe benefits such as refining my ability to self-deny indulgences and be more thoughtful around food choices. Simply put, if I tell my self "no food after 8pm" I won't binge eat two pints of icecream before bed. The only diet that matters is that one you can stick to.
HorizonXP 9y ago
I have been doing intermittent fasting (IF) on a 16/8 or 18/6 schedule for the last 6 weeks. In combination with keto/LCHF food, keeping my daily caloric intake under 1550, and weight lifting 3x weekly, I've been losing 2.5 lbs/week on average. IF fits my lifestyle really well, since I only end up eating twice. I feel super energetic and focused while I'm fasted, and the lack of insulin spikes when I do eat have helped too. Besides losing weight, my overall health seems better. Cuts and injuries heal faster, less facial acne (I didn't have a lot to begin with though), and all of my stomach/intestinal issues are gone. IF works really well for me, and I highly recommend that people try it for themselves for 1-2 months, to see if it works for them too.
- marksc 9y ago
  >I have been doing intermittent fasting (IF) on a 16/8 or 18/6 schedule for the last 6 weeks. What do 16/8 and 18/6 mean in this context?
  - seveneightn9ne 9y ago
    fasting hours/eating hours. So eating within an 8 or 6 hour window each day, and fasting for the other 16 or 18
  - deleted 9y ago
    [deleted]
- TACIXAT 9y ago
  If you have digestion issues you should do an elimination diet. It's nice to identify the cause(s) so you can avoid it in the future. I've given up a lot of foods (that made me feel horrible) and generally eat 1 meal around 11:30am and then snack in the evening. It's so nice getting the diet right. I feel so good now. All of my health issues were caused by foods (I recognize this isn't the case for everyone, but it's worth a shot). Cutting out sugar is awesome. After I did it I really recognized that I was just maintaining a blood sugar high all day long.
  - kbart 9y ago
bmcusick 9y ago
"Calorie restriction is proven to help you live a longer life." This is essentially false for anyone reading the article. The studies that showed mice living longer lives from calorie restriction were restricted from birth, and thus their growth was stunted, and smaller creatures live longer (think about dogs; big ones die earlier). Studies of animals where the calories restriction was started mid-life all show increased mortality. The immune system and wound healing are compromised. That being said, I've been using a system basically like Leangains since March for the purpose of losing weight. It's just cutting calories and I find that two meals a day plus a big plate of vegetables for dinner allows me to fast from Noon to breakfast the next day with minimal hunger. But this is a calorie deficit/weight loss strategy because I'm overweight, not a lifestyle thing I'm going to keep up forever. And so far I've lost 29 lbs since March, so that's nice. There are benefits to fasting occasionally I think, but that's not calorie restriction. It's just giving your body a 24 hr period to engage in autophagy and clear out some of the junk; you make up the calories on the other days.
- nxsynonym 9y ago
  "It's just giving your body a 24 hr period to engage in autophagy and clear out some of the junk; you make up the calories on the other days." Very true. People don't realize that calories don't "reset' after the day ends. Net calorie gain/loss is best measure on a weekly or bi-weekly basis. If you stay under target for 3 days then binge two full pizzas, you aren't actually going to lose anything.
  - buserror 9y ago
    That's not exactly true, if you actually fast for 3 days, even two pizzas won't make up for the lost calories of a 3 days fast, and it's very likely won't be able to eat 2 pizzas in one go.. I know, I fast regularly (I'm days 2 of a 5 day one at the minute) and I do eat quite a lot when I'm not fasting, and despite what everyone will tell you, I don't 'put back the weight immediately' -- even if I have a nice binge dinner on day 5. In fact, after quite a few years of fasting very intermittently (I do perhaps 4 a year), I know I can't eat as much as I used to, and I don't 'creep' up as I used to when I started. I'm a LOT dryer than I was, and I can still enjoy a 32 ounce steak (!) when I feel like one.
m00x 9y ago
I'm a big fan of intermittent fasting, but this article lacks any kind of proof on many of the cited benefits: > Benefit #2. It helps with calorie restriction No study cited that proves this. Only cites studies about the benefits of "proof" that caloric restriction helps longevity, but really is just a correlation. > Benefit #3. It helps you lose weight and body fat No study cited, follows up with "believe me, it worked on me". Cites this study: "Alternate day calorie restriction improves clinical findings and reduces markers of oxidative stress and inflammation in overweight adults with moderate asthma." That's incredibly specific and shouldn't be generalized to the general population. >Benefit #5. It helps your cells clean and repair themselves Cites studies made on rats/mice. Although that's a good indicator it might be mirrored in humans, it proves nothing. > Benefit #7. It regenerates the immune system Study was made on 3 day fasts, and not intermittent fasting. It would nice if he pointed out those are potential benefits instead.
- ktRolster 9y ago
  I've found there is one very real benefit of fasting: it makes food taste better.
  - nicolashahn 9y ago
    If it tastes better because of your appetite, then that's basically just sacrificing some pleasure of not being hungry for the pleasure of the taste of food, like hitting your head against a wall because it feels so good when you stop. (disclaimer: I practice IF but take issue with this one claim, at least without the stipulation of hunger)
    - wahern 9y ago
      If you fast for several days, by about the 3rd or 4th day your sense of smell becomes much more sensitive. It's an interesting and memorable experience--almost like developing a super power--but for some reason whenever I describe this experience to people they don't seem to put it in the "pro" column.
gricardo99 9y ago
Could any one point me to advice/guidance, or can answer from experience, what you would do differently when doing IF with regular exercise? It seems to me you'd want to make some adjustments to types and amounts of calories to account for exercise, especially anything very taxing, like endurance training. But I haven't found any advice on this specific topic.
- buckhx 9y ago
  Basically eat the extra calories you expended. Calculate your TDEE (Total Daily Energy Expenditure) in a purely sedentary state. Then eat more than that on the days you exercise to compensate for the energy you burned. That assumes your goal is to maintain your current weight.
- thechao 9y ago
  I do StrongLifts 5x5 with a 2/5 IF (Mon/Tues). I can have motivation issues on Wed but, otherwise, I've not noticed anything. Cardio is much harder---you've got no "startup" cushion.
- rednerrus 9y ago
  http://www.leangains.com/2010/04/leangains-guide.html http://www.leangains.com/2010/04/leangains-guide.html This worked really well for me.
- e59d134d 9y ago
  I don't have advice but my personal experience is that lifting weights is easy but cardio is almost impossible. I don't really fast on purpose but I mostly eat one large meal a day (dinner). I workout in evenings before dinner. I do snack if I get hungry maybe around 4PM. My snacks are usually Lay's chips. Sometimes, I get a Gatorade for gym. I can lift about as heavy as if I had a big lunch but cardio is different story. If push myself as hard as one days when I had lunch or a lot snacks, I will start to see stars. I go a lot slower with cardio then. (Seeing stars or vision going white is sign of sudden drop in blood sugar level).
liamcardenas 9y ago
I do intermittent fasting (16/8) every day and have found immense benefits. More specifically, I do what's called "time-restricted feeding" in which I only eat between 7am and 2pm (so if I start eating at 10am then I can only eat for 5 more hours). I also strategically eat in the morning because I that is when people are most glucose sensitive. So far I have almost lost 20lb without changing anything in my diet (I currently am 6ft and 200lb). I did not expect this result going in, but have been pleasantly surprised. Research shows that IF can lead to a slight weight loss, but nothing like what I have experienced-- so I wouldn't want anyone to think they can replicate my results. That being said, I would do this even if I did not lose weight because the health benefits are immense.
- snvzz 9y ago
  Been doing this for ages without intending to. I generally eat 13-14 and again 18-19. and that's it.
gxs 9y ago
For the 16+8 routine, does anyone have an idea of how you're supposed to carb cycle?
- arohner 9y ago
  Read the leangains links elsewhere in the thread. In those, Berkham recommends high protein,medium/high carb, low fat on weightlifting days, and high protein, medium fat, low carb on non-weightlifting days.
lolc 9y ago
Intermittent fasting may be good, but factual errors in this piece made me stop reading further. It seems the author didn't study the topic well enough to write about it. Others have already pointed out dubious claims about increased longevity. I'll take issue with section "Benefit #1. It supports with hormone regulation and lowers diabetes II risk." Sure eating less carbohydrates will lower your diabetes risk. But that doesn't mean you have to fast, just that you should eat less carbohydrates. And contrary to what is written under that heading, insulin lowers high sugar levels, it does not cause them. High insulin levels are caused by high blood sugar. While it is plausible that fasting will lower your risk of diabetes, that's foremost because you're eating less and thus the glycemic load is lower. (Glycemic load is how much your blood sugar rises from food.) You can lessen the load by eating less in quantity or by refining carbohydrates less (by eating fruits instead of drinking juice, for example) While I think that fasting is a valid and rather easy way of countering unhealthy eating habits, it is just one of many possible ways. And this is no myth: "If you go too long without food your body will start eating itself (muscle)". The article lists this together with other myths, as if starvation weren't a real danger. Sure most people won't get any ill effects from not eating for a day (it's healthy for most) but once the fat is gone, muscle is next.
inetsee 9y ago
One diet I read about recently that I found interesting is called the Fasting-Mimicking Diet. It's not a strict fasting diet; you spend five contiguous days per month eating a very specific diet of about 1100 calories per day. The diet is low in carbs, low in protein and relatively high in unsaturated fat. One of its claimed benefits is that it's easier to stay on than the other strict fasting diets. Some of its other claimed benefits sound quite amazing. References: http://sciencebulletin.org/archives/10692.html http://sciencebulletin.org/archives/10692.html http://www.bbc.com/news/health-39070183 http://www.bbc.com/news/health-39070183
jimmcslim 9y ago
Any guidance on the risks of IF for folks with Hashimoto's Disease/hypothyroidism?
siliconc0w 9y ago
I find IF helpful to regulate calories. Basically I skip breakfast, eat a light lunch around 1, and a large protein/veg heavy dinner. This is effective if I stick to it (and I generally have for quite some time now). You can't do IF, eat crap, and expect results. You still need a disciplined diet. For me I found I basically need to severely restrict carbs. I will overeat carbs but not protein/less starchy veg. Try eating a BigMac's calories in spinach. It isn't going to happen. As other people have mentioned, a lot of the claims made about IF aren't entirely backed by the research. Most experiments are with mice and usually use a more severe form of fasting that what is advocated. It's just another way to do caloric restriction which may work better than the previous 'best practice' of 'many small meals'.
- adrianmonk 9y ago
  "Basically I skip breakfast, eat a light lunch around 1, and a large protein/veg heavy dinner." Apparently you are my dietary twin. I came to this exact formula accidentally, though, as a result of calorie counting. I skipped breakfast because I could do that most easily. Then I decided lunch would be really light because that gave me the leeway to have a more satisfying dinner and feel completely full once a day. And I didn't want to take the risk of having a light dinner, being hungry, and being unable to get to sleep. I ended up with the mix of protein- and vegetable-heavy dinner because I started reading the nutrition labels of absolutely everything. Then without seeking out a particular type of food, I tried to remember which foods seemed like a good combination of filling and low calorie. And protein and vegetables is what it ended up being. Overall it has worked great. The types and amounts of food I eat feel normal now, and I feel good, and my ability to control my weight has surpassed all expectations.
logicalmike 9y ago
I've cycled through many methods of eating, trying to find an optimal diet to pair with heavy weight training for 6-7 days a week.. while at the same time keeping my weight more or less the same (with only slight fluctuations). Intermittent fasting (or more specifically, following a loose version of the Renegade Diet) is where I landed.. and have been able to keep my weight steady while still making strength gains. In my opinion, it's a good choice who have a hard time controlling their food intake without the hassle of counting calories and/or macros. This way, rules are set, and then can look forward to ~4 hours of eating without restriction. I've pushed this feeding window to the limit, and to gain significant amounts of weight week over week, I basically had to eat until I physically sick for multiple days. I've also had blood work done, with everything being normal since I started over a year ago.
- thrownblown 9y ago
  I've been playing with IF and high activity too, and have been struggling to find a good balance. My sport (track cycling) is very power intensive and has both strength and endurance components. I have two eating periods on active days and one on my rest days. That seems to do me ok, but endurance has still been an issue.
  - logicalmike 9y ago
    It's hard to know without seeing what you eat, but are you sure it's enough? Have you tried tracking a few days to see if you're hitting high enough calories? I'm really stuffing myself at night.. and from others I've talked to, it's very easy for them to under-eat.
bfred_it 9y ago
Why is this stuff on HN? It reads as pseudo-science.
- jo909 9y ago
  So we can discuss it in a constructive manner, for example by pointing out what makes this pseudo-science and why it might be not the worst idea anyway. Like other commenters have done, and I enjoyed reading their arguments.
nsxwolf 9y ago
Even if IF is nothing more than calorie restriction supporting the calories in/calories out hypothesis, it succeeds in creating a real psychological benefit - you get to have real, satisfying meals of food you actually like - you just have to wait longer for it. If you're trying to lose weight, and you like food, the sight of the food in these 1200 calorie 3 meal daily plans is incredibly depressing. Eating an egg white on a piece of wheat toast every morning for the rest of your life is a kind of torture that never gets easier. It's like trying not to blink forever, or holding your breath forever. Much better to just wait all day and spend the calories on a generous portion of something you really want to eat.
- agumonkey 9y ago
  I'm aiming at this these days. I'm cutting most shitty food (I allow some pastry in the week; but no soda, no fast food, no industrial meals). But I'm not mentally ready to cut the pleasure of a good meal. I'll better stop using my car and job between places and keep higher calories. I "believe" the benefits of good ingredients, close to no fat and no added sugar + regular sport is already significant. Later I'll move to more vegetables, less carbohydrates to trim my body fat even further.
  - majewsky 9y ago
    > I'll better stop using my car and job between places I suppose you mean "jog", but jobbing between places sounds very intense as well. :)
    - agumonkey 9y ago
      Indeed, keyboard slip.
cybervegan 9y ago
I did intermittent fasting 2 days a week for 2 years (2013-2015). Initially I lost weight, which was good. Energy levels were elevated, minor health problems seemed to have gone away or lessened. Towards the end, I think I was being rather too "soft" on myself, so wasn't really reaping the benefits, and it got to be a grind. I then had some rather unpleasant emotional issues to deal with, and found I didn't have the emotional energy to continue: I have pretty decent willpower, but when I'm badly emotionally stressed, it crumbles. I've been intending to get back into I/F ever since, and though I'm emotionally in a far better place, I haven't managed to muster the emotional energy for it yet.
KVFinn 9y ago
I really like the most moderate form -- simply eat two meals a day, skipping either your first meal in the day or your last. Everyone 'fasts' for 8 - 12 hours just by sleeping anyway, so simply skipping one meal nearest sleep means you fast for about 16h a day.
SuperGent 9y ago
-Stop eating at 8pm (the time of my last meal) -Start eating at 1 or 2pm the following day How is this just not just skipping breakfast? 3 times a week? I know lots of overweight people who do this, although it is easy to follow.
- majewsky 9y ago
  From personal experience [1], even when I have only two big meals, I'll eat a ton of snacks of sweets during the whole day. Cutting these out is the large difference to "just skipping breakfast". [1] Have not done any fasting, but recently started considering intermittent fasting.
zamber 9y ago
There's a net of dieting resorts around Poland doing "Dieta Dąbrowskiej" among some other health-oriented stuff. In essence it's calorie restriction on veggies for 2-6 weeks at a time supplemented with blood tests and physical activity. She (Dąbrowska) states that it resets the immune system, restricts cancer growth (or even puts cancers into recession), helps with diabetes and cures food intolerance. Proof for it is provided as "I've seen people that improved". I'm highly skeptical about it as my vegan-celiac-fit family part got hyped for it and went through a 3 week run. They came back with anecdotal self-healing miracles. The diet is around 600-700 kcal a day, low on sugar. Supposedly it stimulates autophagy giving all of the stated benefits (on top of cleansing out "toxins"). As a side note I found that food intolerance is in fashion recently. There's one (!) test offered in my area for it called the Food Detective (made by Cambridge Nutritional Sciences Ltd.). I'm highly skeptical of it too as there's no competition and I couldn't find any studies confirming it's effectiveness. My main concern is the potential impact on the brain. I vaguely recall some study observing neuron loss during extended periods of starvation. Also having some sensible studies to back it up (or debunk it) would be nice.
- reitanqild 9y ago
  With you on the scepticism esp. about the detox-thing. That said fasting in some form seems to have been with us for a few thousand years and it seems unlikely that it would be so widely documented and practiced across cultures and religions if there wasn't some benefits to it.

192 points by hunglee2 9y ago

Overall the body is pretty good at nutrient partitioning and maintaining a caloric balance. There may be small statistically different outcomes for practicing stuff like IF, but there aren't clinically different outcomes outside of using IF to maintain compliance to a diet. If IF helps you maintain your ability to comply to the diet you want, great, but there's absolutely no evidence for it being superior than the same diet spread over the day, and there a few ways in which it's probably suboptimal, like building muscle (although again not hugely so, so compliance probably trumps the small advantage you get).

jraby3 9y ago
What about in controlling insulin resistance? I thought the data was pretty strong in favor of IF helping significantly.
- wdewind 9y ago
  It's not. The same amount of glycemic load consumed all at once or over time throughout the day will not have a significant effect on insulin resistance. Not being able to eat as much because you are constrained to an 8 hour window will cause your overall glycemic load to go down.

bykovich2 9y ago

"Calorie restriction is proven to help you live a longer life." Flatly untrue. The article linked to "in proof" is about primate studies that suggest -- perhaps even strongly suggest -- that caloric restriction can slow the process of aging. This does not, however, rise to the level of proof, and certainly does not provide conclusive indication of what caloric restricters can expect more generally. The author is apparently willing to make this grandiose claim to a susceptible audience with nary a word about its limitations, which should set our alarm bells ringing. If you want to calorically restrict, do it because you've thought long and hard about the consequences of a truly significant choice -- not because it's a tech industry fad.

HorizonXP 9y ago
I think the phenomenon is poorly understood and studied, but it's likely not the calorie restriction itself, like you claim. Apparently it has to do with autophagy (https://en.wikipedia.org/wiki/Autophagy https://en.wikipedia.org/wiki/Autophagy), which your body seems to enter when you restrict calories. IF apparently stimulates your body to perform autophagy due to the fact that you're timing your meals. TBH, I still need to do my own research to see how much of this is real vs. pseudoscience, but I've noticed an improvement to my health. Whether that's placebo effect or not, remains to be seen.
- allover 9y ago
  Well GPP is just saying that 'calorie restriction' is not proven to 'help you live a longer life', irrespective of the IF context. As for IF, as you say, it is basically not proven to do anything (no 'phenomenon' at all). Simplest and most logical reason for success is because it helps people stick to their diet, by arbitrarily restricting the window of eating. Opinion I read on r/leangains is that some people find it easier to e.g. just eat two 600-800 calorie meals within their IF window, rather than sticking to a diet that involves 3-4 smaller ~300-400 calorie meals, spread out through the day, none of which feel 'satisfying'.
nxsynonym 9y ago
I agree, and this can be applied to every single diet fab that's been talked/tweeted/click-baited about in the past 10 years. I do IF, but that's because if I try to eat anything within 3 or 4 hours of waking up I feel nauseous and sleepy. I also find it easier to manage caloric intake by limiting my "feeding window" to 8 or 10 hours. There are also some fringe benefits such as refining my ability to self-deny indulgences and be more thoughtful around food choices. Simply put, if I tell my self "no food after 8pm" I won't binge eat two pints of icecream before bed. The only diet that matters is that one you can stick to.

HorizonXP 9y ago

I have been doing intermittent fasting (IF) on a 16/8 or 18/6 schedule for the last 6 weeks. In combination with keto/LCHF food, keeping my daily caloric intake under 1550, and weight lifting 3x weekly, I've been losing 2.5 lbs/week on average. IF fits my lifestyle really well, since I only end up eating twice. I feel super energetic and focused while I'm fasted, and the lack of insulin spikes when I do eat have helped too. Besides losing weight, my overall health seems better. Cuts and injuries heal faster, less facial acne (I didn't have a lot to begin with though), and all of my stomach/intestinal issues are gone. IF works really well for me, and I highly recommend that people try it for themselves for 1-2 months, to see if it works for them too.

marksc 9y ago
>I have been doing intermittent fasting (IF) on a 16/8 or 18/6 schedule for the last 6 weeks. What do 16/8 and 18/6 mean in this context?
- seveneightn9ne 9y ago
  fasting hours/eating hours. So eating within an 8 or 6 hour window each day, and fasting for the other 16 or 18
- deleted 9y ago
  [deleted]
TACIXAT 9y ago
If you have digestion issues you should do an elimination diet. It's nice to identify the cause(s) so you can avoid it in the future. I've given up a lot of foods (that made me feel horrible) and generally eat 1 meal around 11:30am and then snack in the evening. It's so nice getting the diet right. I feel so good now. All of my health issues were caused by foods (I recognize this isn't the case for everyone, but it's worth a shot). Cutting out sugar is awesome. After I did it I really recognized that I was just maintaining a blood sugar high all day long.
- kbart 9y ago

bmcusick 9y ago

"Calorie restriction is proven to help you live a longer life." This is essentially false for anyone reading the article. The studies that showed mice living longer lives from calorie restriction were restricted from birth, and thus their growth was stunted, and smaller creatures live longer (think about dogs; big ones die earlier). Studies of animals where the calories restriction was started mid-life all show increased mortality. The immune system and wound healing are compromised. That being said, I've been using a system basically like Leangains since March for the purpose of losing weight. It's just cutting calories and I find that two meals a day plus a big plate of vegetables for dinner allows me to fast from Noon to breakfast the next day with minimal hunger. But this is a calorie deficit/weight loss strategy because I'm overweight, not a lifestyle thing I'm going to keep up forever. And so far I've lost 29 lbs since March, so that's nice. There are benefits to fasting occasionally I think, but that's not calorie restriction. It's just giving your body a 24 hr period to engage in autophagy and clear out some of the junk; you make up the calories on the other days.

nxsynonym 9y ago
"It's just giving your body a 24 hr period to engage in autophagy and clear out some of the junk; you make up the calories on the other days." Very true. People don't realize that calories don't "reset' after the day ends. Net calorie gain/loss is best measure on a weekly or bi-weekly basis. If you stay under target for 3 days then binge two full pizzas, you aren't actually going to lose anything.
- buserror 9y ago
  That's not exactly true, if you actually fast for 3 days, even two pizzas won't make up for the lost calories of a 3 days fast, and it's very likely won't be able to eat 2 pizzas in one go.. I know, I fast regularly (I'm days 2 of a 5 day one at the minute) and I do eat quite a lot when I'm not fasting, and despite what everyone will tell you, I don't 'put back the weight immediately' -- even if I have a nice binge dinner on day 5. In fact, after quite a few years of fasting very intermittently (I do perhaps 4 a year), I know I can't eat as much as I used to, and I don't 'creep' up as I used to when I started. I'm a LOT dryer than I was, and I can still enjoy a 32 ounce steak (!) when I feel like one.

m00x 9y ago

I'm a big fan of intermittent fasting, but this article lacks any kind of proof on many of the cited benefits: > Benefit #2. It helps with calorie restriction No study cited that proves this. Only cites studies about the benefits of "proof" that caloric restriction helps longevity, but really is just a correlation. > Benefit #3. It helps you lose weight and body fat No study cited, follows up with "believe me, it worked on me". Cites this study: "Alternate day calorie restriction improves clinical findings and reduces markers of oxidative stress and inflammation in overweight adults with moderate asthma." That's incredibly specific and shouldn't be generalized to the general population. >Benefit #5. It helps your cells clean and repair themselves Cites studies made on rats/mice. Although that's a good indicator it might be mirrored in humans, it proves nothing. > Benefit #7. It regenerates the immune system Study was made on 3 day fasts, and not intermittent fasting. It would nice if he pointed out those are potential benefits instead.

ktRolster 9y ago
I've found there is one very real benefit of fasting: it makes food taste better.
- nicolashahn 9y ago
  If it tastes better because of your appetite, then that's basically just sacrificing some pleasure of not being hungry for the pleasure of the taste of food, like hitting your head against a wall because it feels so good when you stop. (disclaimer: I practice IF but take issue with this one claim, at least without the stipulation of hunger)
  - wahern 9y ago
    If you fast for several days, by about the 3rd or 4th day your sense of smell becomes much more sensitive. It's an interesting and memorable experience--almost like developing a super power--but for some reason whenever I describe this experience to people they don't seem to put it in the "pro" column.

gricardo99 9y ago

Could any one point me to advice/guidance, or can answer from experience, what you would do differently when doing IF with regular exercise? It seems to me you'd want to make some adjustments to types and amounts of calories to account for exercise, especially anything very taxing, like endurance training. But I haven't found any advice on this specific topic.

buckhx 9y ago
Basically eat the extra calories you expended. Calculate your TDEE (Total Daily Energy Expenditure) in a purely sedentary state. Then eat more than that on the days you exercise to compensate for the energy you burned. That assumes your goal is to maintain your current weight.
thechao 9y ago
I do StrongLifts 5x5 with a 2/5 IF (Mon/Tues). I can have motivation issues on Wed but, otherwise, I've not noticed anything. Cardio is much harder---you've got no "startup" cushion.
rednerrus 9y ago
http://www.leangains.com/2010/04/leangains-guide.html http://www.leangains.com/2010/04/leangains-guide.html This worked really well for me.
e59d134d 9y ago
I don't have advice but my personal experience is that lifting weights is easy but cardio is almost impossible. I don't really fast on purpose but I mostly eat one large meal a day (dinner). I workout in evenings before dinner. I do snack if I get hungry maybe around 4PM. My snacks are usually Lay's chips. Sometimes, I get a Gatorade for gym. I can lift about as heavy as if I had a big lunch but cardio is different story. If push myself as hard as one days when I had lunch or a lot snacks, I will start to see stars. I go a lot slower with cardio then. (Seeing stars or vision going white is sign of sudden drop in blood sugar level).

liamcardenas 9y ago

I do intermittent fasting (16/8) every day and have found immense benefits. More specifically, I do what's called "time-restricted feeding" in which I only eat between 7am and 2pm (so if I start eating at 10am then I can only eat for 5 more hours). I also strategically eat in the morning because I that is when people are most glucose sensitive. So far I have almost lost 20lb without changing anything in my diet (I currently am 6ft and 200lb). I did not expect this result going in, but have been pleasantly surprised. Research shows that IF can lead to a slight weight loss, but nothing like what I have experienced-- so I wouldn't want anyone to think they can replicate my results. That being said, I would do this even if I did not lose weight because the health benefits are immense.

snvzz 9y ago
Been doing this for ages without intending to. I generally eat 13-14 and again 18-19. and that's it.

gxs 9y ago

For the 16+8 routine, does anyone have an idea of how you're supposed to carb cycle?

arohner 9y ago
Read the leangains links elsewhere in the thread. In those, Berkham recommends high protein,medium/high carb, low fat on weightlifting days, and high protein, medium fat, low carb on non-weightlifting days.

lolc 9y ago

Intermittent fasting may be good, but factual errors in this piece made me stop reading further. It seems the author didn't study the topic well enough to write about it. Others have already pointed out dubious claims about increased longevity. I'll take issue with section "Benefit #1. It supports with hormone regulation and lowers diabetes II risk." Sure eating less carbohydrates will lower your diabetes risk. But that doesn't mean you have to fast, just that you should eat less carbohydrates. And contrary to what is written under that heading, insulin lowers high sugar levels, it does not cause them. High insulin levels are caused by high blood sugar. While it is plausible that fasting will lower your risk of diabetes, that's foremost because you're eating less and thus the glycemic load is lower. (Glycemic load is how much your blood sugar rises from food.) You can lessen the load by eating less in quantity or by refining carbohydrates less (by eating fruits instead of drinking juice, for example) While I think that fasting is a valid and rather easy way of countering unhealthy eating habits, it is just one of many possible ways. And this is no myth: "If you go too long without food your body will start eating itself (muscle)". The article lists this together with other myths, as if starvation weren't a real danger. Sure most people won't get any ill effects from not eating for a day (it's healthy for most) but once the fat is gone, muscle is next.

inetsee 9y ago

One diet I read about recently that I found interesting is called the Fasting-Mimicking Diet. It's not a strict fasting diet; you spend five contiguous days per month eating a very specific diet of about 1100 calories per day. The diet is low in carbs, low in protein and relatively high in unsaturated fat. One of its claimed benefits is that it's easier to stay on than the other strict fasting diets. Some of its other claimed benefits sound quite amazing. References: http://sciencebulletin.org/archives/10692.html http://sciencebulletin.org/archives/10692.html http://www.bbc.com/news/health-39070183 http://www.bbc.com/news/health-39070183

jimmcslim 9y ago

Any guidance on the risks of IF for folks with Hashimoto's Disease/hypothyroidism?

siliconc0w 9y ago

I find IF helpful to regulate calories. Basically I skip breakfast, eat a light lunch around 1, and a large protein/veg heavy dinner. This is effective if I stick to it (and I generally have for quite some time now). You can't do IF, eat crap, and expect results. You still need a disciplined diet. For me I found I basically need to severely restrict carbs. I will overeat carbs but not protein/less starchy veg. Try eating a BigMac's calories in spinach. It isn't going to happen. As other people have mentioned, a lot of the claims made about IF aren't entirely backed by the research. Most experiments are with mice and usually use a more severe form of fasting that what is advocated. It's just another way to do caloric restriction which may work better than the previous 'best practice' of 'many small meals'.

adrianmonk 9y ago
"Basically I skip breakfast, eat a light lunch around 1, and a large protein/veg heavy dinner." Apparently you are my dietary twin. I came to this exact formula accidentally, though, as a result of calorie counting. I skipped breakfast because I could do that most easily. Then I decided lunch would be really light because that gave me the leeway to have a more satisfying dinner and feel completely full once a day. And I didn't want to take the risk of having a light dinner, being hungry, and being unable to get to sleep. I ended up with the mix of protein- and vegetable-heavy dinner because I started reading the nutrition labels of absolutely everything. Then without seeking out a particular type of food, I tried to remember which foods seemed like a good combination of filling and low calorie. And protein and vegetables is what it ended up being. Overall it has worked great. The types and amounts of food I eat feel normal now, and I feel good, and my ability to control my weight has surpassed all expectations.

logicalmike 9y ago

I've cycled through many methods of eating, trying to find an optimal diet to pair with heavy weight training for 6-7 days a week.. while at the same time keeping my weight more or less the same (with only slight fluctuations). Intermittent fasting (or more specifically, following a loose version of the Renegade Diet) is where I landed.. and have been able to keep my weight steady while still making strength gains. In my opinion, it's a good choice who have a hard time controlling their food intake without the hassle of counting calories and/or macros. This way, rules are set, and then can look forward to ~4 hours of eating without restriction. I've pushed this feeding window to the limit, and to gain significant amounts of weight week over week, I basically had to eat until I physically sick for multiple days. I've also had blood work done, with everything being normal since I started over a year ago.

thrownblown 9y ago
I've been playing with IF and high activity too, and have been struggling to find a good balance. My sport (track cycling) is very power intensive and has both strength and endurance components. I have two eating periods on active days and one on my rest days. That seems to do me ok, but endurance has still been an issue.
- logicalmike 9y ago
  It's hard to know without seeing what you eat, but are you sure it's enough? Have you tried tracking a few days to see if you're hitting high enough calories? I'm really stuffing myself at night.. and from others I've talked to, it's very easy for them to under-eat.

bfred_it 9y ago

Why is this stuff on HN? It reads as pseudo-science.

jo909 9y ago
So we can discuss it in a constructive manner, for example by pointing out what makes this pseudo-science and why it might be not the worst idea anyway. Like other commenters have done, and I enjoyed reading their arguments.

nsxwolf 9y ago

Even if IF is nothing more than calorie restriction supporting the calories in/calories out hypothesis, it succeeds in creating a real psychological benefit - you get to have real, satisfying meals of food you actually like - you just have to wait longer for it. If you're trying to lose weight, and you like food, the sight of the food in these 1200 calorie 3 meal daily plans is incredibly depressing. Eating an egg white on a piece of wheat toast every morning for the rest of your life is a kind of torture that never gets easier. It's like trying not to blink forever, or holding your breath forever. Much better to just wait all day and spend the calories on a generous portion of something you really want to eat.

agumonkey 9y ago
I'm aiming at this these days. I'm cutting most shitty food (I allow some pastry in the week; but no soda, no fast food, no industrial meals). But I'm not mentally ready to cut the pleasure of a good meal. I'll better stop using my car and job between places and keep higher calories. I "believe" the benefits of good ingredients, close to no fat and no added sugar + regular sport is already significant. Later I'll move to more vegetables, less carbohydrates to trim my body fat even further.
- majewsky 9y ago
  > I'll better stop using my car and job between places I suppose you mean "jog", but jobbing between places sounds very intense as well. :)
  - agumonkey 9y ago
    Indeed, keyboard slip.

cybervegan 9y ago

I did intermittent fasting 2 days a week for 2 years (2013-2015). Initially I lost weight, which was good. Energy levels were elevated, minor health problems seemed to have gone away or lessened. Towards the end, I think I was being rather too "soft" on myself, so wasn't really reaping the benefits, and it got to be a grind. I then had some rather unpleasant emotional issues to deal with, and found I didn't have the emotional energy to continue: I have pretty decent willpower, but when I'm badly emotionally stressed, it crumbles. I've been intending to get back into I/F ever since, and though I'm emotionally in a far better place, I haven't managed to muster the emotional energy for it yet.

KVFinn 9y ago

I really like the most moderate form -- simply eat two meals a day, skipping either your first meal in the day or your last. Everyone 'fasts' for 8 - 12 hours just by sleeping anyway, so simply skipping one meal nearest sleep means you fast for about 16h a day.

SuperGent 9y ago

-Stop eating at 8pm (the time of my last meal) -Start eating at 1 or 2pm the following day How is this just not just skipping breakfast? 3 times a week? I know lots of overweight people who do this, although it is easy to follow.

majewsky 9y ago
From personal experience [1], even when I have only two big meals, I'll eat a ton of snacks of sweets during the whole day. Cutting these out is the large difference to "just skipping breakfast". [1] Have not done any fasting, but recently started considering intermittent fasting.

zamber 9y ago

There's a net of dieting resorts around Poland doing "Dieta Dąbrowskiej" among some other health-oriented stuff. In essence it's calorie restriction on veggies for 2-6 weeks at a time supplemented with blood tests and physical activity. She (Dąbrowska) states that it resets the immune system, restricts cancer growth (or even puts cancers into recession), helps with diabetes and cures food intolerance. Proof for it is provided as "I've seen people that improved". I'm highly skeptical about it as my vegan-celiac-fit family part got hyped for it and went through a 3 week run. They came back with anecdotal self-healing miracles. The diet is around 600-700 kcal a day, low on sugar. Supposedly it stimulates autophagy giving all of the stated benefits (on top of cleansing out "toxins"). As a side note I found that food intolerance is in fashion recently. There's one (!) test offered in my area for it called the Food Detective (made by Cambridge Nutritional Sciences Ltd.). I'm highly skeptical of it too as there's no competition and I couldn't find any studies confirming it's effectiveness. My main concern is the potential impact on the brain. I vaguely recall some study observing neuron loss during extended periods of starvation. Also having some sensible studies to back it up (or debunk it) would be nice.

reitanqild 9y ago
With you on the scepticism esp. about the detox-thing. That said fasting in some form seems to have been with us for a few thousand years and it seems unlikely that it would be so widely documented and practiced across cultures and religions if there wasn't some benefits to it.