It's hilarious that people describe their anecdotal experience of being in a calorie deficit as a proof that "intermittent fasting works".
This was never the question, but whether intermittent fasting brings additional weight loss benefits as compared to calorie deficit with frequent meals.
My anecdotal experience from 20y of bodybuilding and doing ~3 cuts a year: for cutting, I tried IF, 6 meals a day, low fat, low carb, high fat true keto, balanced... everything works. And works equally well - this is backed by numerous studies. The only difference is the impact on health parameters (different will get worse on low fat vs high fat), satiety, and how easy it is for someone to sustain the diet and stay in a deficit. This will depend on the lifestyle and personal preferences. So my preferred way to cut is high protein, low carb, essential fats, a ton of fiber. When building muscle I go high everything but balanced.
Anything else and more is sectarianism and people bragging about their choices not having verified their true claimed efficacy or benefits.
> Anything else and more is sectarianism and people bragging about their choices not having verified their true claimed efficacy or benefits.
Everybody's looking for a silver bullet and wants to advocate for their specific one by tearing competing theories down. The reason that IF works is because it's more difficult to eat at a caloric surplus when you can only fill your stomach for 8 hours a day. Full stop. There might be modest ancillary benefits but as far as weight loss it really is as simple as calories in versus calories out. There are tons of variations on this theme dependent on goals and tolerance for discomfort but simple math wins ten times out of ten.
For the layperson IF or keto or something similarly extreme is effective but difficult. It requires strict adherence to a lifestyle that impacts one's social life and makes eating prepared foods difficult. Worst of all it leads to impromptu cheat days in moments of weakness that spiral out of control and negatively affect consistency. For people trying to lead a normal life I personally think eating at 80% TDEE with 1:1:1 macros is the most sustainable - you eat at your leisure, get sufficient protein for lean muscle mass and still eat carbs for energy and fun. It's basically "eat less, have a protein shake." Combine this with some light cardio and body weight/kettlebell stuff while watching TV and you'll see great functional fitness gains in addition to quick and steady weight loss.
Of course it's hard to build an online quasi-religion around moderation so this type of thinking isn't mainstream despite its efficacy.
Totally agree, you have to figure it out for yourself. Not only do these diets affect people differently, they also affect each individual differently throughout their life. IF might be great when you are 45 but no good when you are 20.
I really struggled to get lighter a few years ago and what ended up working finally was cutting my protein way down. After repeated failures with high protein/low carb, I finally just went for low protein despite no diet recommending it. It worked great, I lost muscle but it made satiety way easier and my body naturally seemed to shift to a lighter composition.
I still don't see any diets recommending that. It seems like a useful tool, especially given how "fitness" nowadays is lifting weights and chugging protein, there are going to be a ton of dudes in their 30s/40s who put on a boatload of muscle in their youth and now are struggling to get lighter using all the recommended high protein diets. If you don't give the muscle up satiety is going to make it an insane battle.
> The only difference is the impact on health parameters (different will get worse on low fat vs high fat), satiety, and how easy it is for someone to sustain the diet and stay in a deficit.
That was never the question or point. It was that’s it’s easier to adhere to intermittent fasting and consume less calories. So if you simply did a study comparing intermittent fasting vs general calorie restriction and didn’t control for calories then intermittent fasting would win. Controlling for calories completely misses the point
This study is measuring the wrong thing. Any diet that restricts calories will cause weight loss, that's just physics not biology. So long as the person strictly sticks to that diet it will work.
Strategies like intermittent fasting or diets that moderate what you eat rather than quantity are focused on the later aspect "strictly sticking to that diet". Because being strict is not sustainable, will power is limited and inconsistent, so wasting it on strategies that are hard to stick to is both futile and a waste of will power. Changing what and when you eat accounts for biology instead of just physics, because those variables have a huge impact on satiety.
The study has a minimum interval of 4 weeks, which does not take much will power. Not to mention the psychological impact of being part of a study.
Imo what many discussions on IF miss is that one of the most challenging aspects in dieting, including in studies/interventions, is adherence rates. You can make a lot of different diets that are more healthy and/or have lower calories than a baseline diet of somebody and lead to losing weight, but the biggest challenge is how one adheres to them.
My experience with IF is that it makes it easier to schedule meals as well as to deal with whatever insatiety feelings come from reducing calories, and this made it easier for me to stay with IF diet than with other diets. I have read research where adherence is significantly higher in IF groups, other where it is lower. Essentially, adherence is firstmost about what works for a specific person. If the diet logistics don't work for you personally, it matters little what statistics say. The point (of any diet for weight loss/management) is always to reduce/control calories intake.
My understanding of intermittent fasting is that it can encourage "garbage collection" of the body pruning the dead/sickly cells. Weight loss/gain is still driven by calories in/out.
It's always calories in and calories out. The idea is that intermittent fasting makes you less hungry over time and thus you take in less calories.
If they had their test subjects eat the same amount to see if intermittent fasting metabolized food better then it seems obvious that there would be little to no difference.
> Intermittent fasting may make little difference to weight loss.
My personal experience is quite the opposite. In fact, this is the first time I have heard anybody claim that intermittent fasting, when done correctly, does not make you lose weight. Sounds like a study done by people who sell weight-loss drugs or meals.
Intermittent fasting is one of the more reliable ways to lose weight.
Personal experience says otherwise. Low carb/slow carb diet plus fasting 100% did it for me. 40 lbs gone, and have kept it off even while backing off of the initial rigidity. Everything in moderation, especially alcohol. Beer is a huge carb load, so that had to go entirely. Pasta as well. Potatoes too. Sure, I have a couple fries (or chippies for the BBC crew), but it’s all about those being scarce. It’s actually pretty easy to intermittent fast. Eat dinner and be done before 8pm and have lunch around 1pm the next day. Have coffee or tea in the morning.
What really accelerated weight loss for me was extremely rigid ketogenesis. Felt amazingly sharp and dialed in every morning, slept well, shredded pounds.
In a couple of days ~2 billion people world-wide will begin intermittent fasting, done from dawn to sunset, for a month, which is one of the components of the month of Ramadan. Nobody does this to lose weight, or even changes their diet, yet everyone loses some weight. 5lb is typical. Most people who fast Ramadan also gain it back afterward because they didn't make any changes to their diet, which points to the effectiveness of intermittent fasting to lose weight.
There is one difference between Ramadan fasting and modern intermittent fasting: Ramadan fasts are 'dry' fasts no water is imbibed and the alimentary canal stays completely unstimulated for long periods of time.
You don't lose less/more weight if you have the same calories input without intermittent fasting. That's well established and the study doesn't show anything surprising.
However, there's more than weight. I wonder if Ramadan has a lasting impact on blood sugar stability, for example.
* I only eat one meal a day (supper). It's usually a very large meal, very high in lean protein.
* I avoid sugars and starches of all kinds and minimize other carbs (fruit, root veg, grains).
* After eating, I do 30 minutes on the treadmill.
For a middle-aged woman (a category which finds it particularly hard to lose weight) this has worked rather well. I can eat as much meat, (non-root) veg, dairy and soy as I want and I just keep losing weight.
How do you know that spreading that one meal out throughout the day wouldn't have the same effect? I bet you'd have more energy as well.
Unless you have tested this, I find it hard to believe that this isn't really just a caloric deficit compared to whatever you were doing before losing weight, assuming the same activity level.
What made the most difference for me was strength training a few times per week. I do circuit training classes where you spend 6 minutes per station. I didn't change my diet that much, and I really didn't lose much weight. But the muscle displaced the fat and I'm slimmer and look better.
Most of the studies they looked at did not use the most robust methods and included small numbers of people, making it difficult to work out the true effects.
Not a good sign for a meta study. When you average garbage you still get garbage.
As for my personal experience, I looked at scientific papers 5 years ago (no, intermittent fasting isn’t some new social media fad). The consensus back then was that it only slightly increases the speed at which one loses weight, but it helps significantly with adherence to a diet.
This was a game changer for me too. With just attempts to control my caloric deficit I failed because I ended up snacking. With intermittent fasting (the strict variant of only eating once after work in my case) I simply had no appetite from the morning until my meal. I also didn’t have cravings before sleep.
> The consensus back then was that it only slightly increases the speed at which one loses weight, but it helps significantly with adherence to a diet.
This is my experience as well. IF didn't teach me how or what o eat, it taught me not to snack after the last meal of the day, and after losing around 10% of my weight (still obesity grade II), the weight-loss effect was lost. It didn't work for long-term weight loss, it just established a new equilibrium. Also, there's a bounce back if you stop it.
Currently, I'm on Mounjaro (diabetes type II likely caused by obesity and genetics), and IF meshes wonderfully with it, since mounjaro forces you to eat less or feel miserable. So far I've reached obesity grade I (aka plain obesity), and the effect has been very consistent over time, no new equilibrium reached yet.
So, for me, IF is not for weight loss, but it helps if you combine it with a proven method for weight loss.
This is how all dieting works. Specific techniques in isolation rarely have a huge impact, but that doesn't actually matter.
Any framework that causes an overwieght person to genuinely pay attention to what they eat will have a weight loss impact, because all you have to do to lose weight is eat less. The wide variety of dieting techniques are a good thing because it maximizes the likelihood that any individual will find a framework that induces them to pay attention to their eating habits.
I've gone through many weight loss cycles using various techniques including OMAD. Eating once a day changes your relationship with food, and disrupting that relationship is a thousand times more important than whatever obscure biological processes the fitness gurus suppose are in play.
How do people that do this exercise? are they mostly sedentary?
I mostly ride bikes for exercise and need fuel at least every hour on a ride or else I will bonk out. My output is 500kcal/hour based on power meter, a 4 hour ride would be 2000kcal, it's not doable without some food intake.
Your body adjusts to using fat as fuel. I’m no scientist/doctor but I’m training for a marathon and I find I perform much better than when using gels or bars or any of that other processed ‘fuel’ I used to use.
I also love weightlifting while being fasted. One meal end of day for me has put me in the best shape I ever have in 36 years. So much that I actually took up running haha.
I also ride bike, and used to bonk, but it didn't take long for my body to adapt to using fat as fuel. Half the battle was mental: accepting that I truly didn't need to eat anything; my body already had all the fuel it needed.
Then I could wake up, ride hard for hours (hilly terrain), and feel no need to eat until the afternoon.
There are two kinds of IF: a skipping a meal kind, when you only eat during a 6-8 hour window and it's easy to fit a 4 hour bike ride in there or a skipping a day kind, when you don't eat every third/fourth day, then you can use the fasting day to do a recovery ride or even rest.
A priori I am very suspicious of any magic diet claims that bring up “inflammation”. I know that chronic inflammation seems to be a major problem among western diets, but that’s exactly why it has become this unfalsifiable catch-all explanation for anyone who wants to sell you something. The seed oil people also smoothly switched to “inflammation” once it became clear there was no correlation between seed oil intake and obesity rates.
I am sure it's personal, but when I fast 24 hours (once per week), the next two days I look for less food, to the point that I can skip lunch without noticing.
The big deal for me is not eating stuff with flour (starch?) or sugar.
I already eat healthy, although I switched from chicken to a full protein tofu that's low on calories and that has been a blessing for protein intake (along with egg white). I can eat 60g of protein at lunch in about 350 calories.
That gives me everything I need for the gym.
My snack is apple with a teaspoon of pure pistachio butter, which calms down my desire for sweets (I love pistachio)
Ya these studies that cut down intermittent fasting always have an 8 hour eating window which is not intermittent fasting. Junk science probably sponsored by the food industry
At some point, we as a society are going to come to grips with the fact that only like 5% of the population is capable of actually losing and maintaining weight-loss.
The rest is just all new "fad diets" that cycle every 3 years as people go through the cycle of trying them, seeing results, failing to maintain them "forever" (which is what they'd have to do), and then putting the weight back on.
Every single diet has this problem (Even GLP-1s from what I have seen). The human body seems to have some mechanism by which it attempts to maintain it's current weight. But we all continue to be incredibly prone to "this new fad diet actually works!"
bartwr|14 days ago
My anecdotal experience from 20y of bodybuilding and doing ~3 cuts a year: for cutting, I tried IF, 6 meals a day, low fat, low carb, high fat true keto, balanced... everything works. And works equally well - this is backed by numerous studies. The only difference is the impact on health parameters (different will get worse on low fat vs high fat), satiety, and how easy it is for someone to sustain the diet and stay in a deficit. This will depend on the lifestyle and personal preferences. So my preferred way to cut is high protein, low carb, essential fats, a ton of fiber. When building muscle I go high everything but balanced.
Anything else and more is sectarianism and people bragging about their choices not having verified their true claimed efficacy or benefits.
alexjplant|14 days ago
Everybody's looking for a silver bullet and wants to advocate for their specific one by tearing competing theories down. The reason that IF works is because it's more difficult to eat at a caloric surplus when you can only fill your stomach for 8 hours a day. Full stop. There might be modest ancillary benefits but as far as weight loss it really is as simple as calories in versus calories out. There are tons of variations on this theme dependent on goals and tolerance for discomfort but simple math wins ten times out of ten.
For the layperson IF or keto or something similarly extreme is effective but difficult. It requires strict adherence to a lifestyle that impacts one's social life and makes eating prepared foods difficult. Worst of all it leads to impromptu cheat days in moments of weakness that spiral out of control and negatively affect consistency. For people trying to lead a normal life I personally think eating at 80% TDEE with 1:1:1 macros is the most sustainable - you eat at your leisure, get sufficient protein for lean muscle mass and still eat carbs for energy and fun. It's basically "eat less, have a protein shake." Combine this with some light cardio and body weight/kettlebell stuff while watching TV and you'll see great functional fitness gains in addition to quick and steady weight loss.
Of course it's hard to build an online quasi-religion around moderation so this type of thinking isn't mainstream despite its efficacy.
ericmcer|14 days ago
I really struggled to get lighter a few years ago and what ended up working finally was cutting my protein way down. After repeated failures with high protein/low carb, I finally just went for low protein despite no diet recommending it. It worked great, I lost muscle but it made satiety way easier and my body naturally seemed to shift to a lighter composition.
I still don't see any diets recommending that. It seems like a useful tool, especially given how "fitness" nowadays is lifting weights and chugging protein, there are going to be a ton of dudes in their 30s/40s who put on a boatload of muscle in their youth and now are struggling to get lighter using all the recommended high protein diets. If you don't give the muscle up satiety is going to make it an insane battle.
WithinReason|14 days ago
Did anybody claim otherwise?
slowmovintarget|14 days ago
unparagoned|13 days ago
tomxor|14 days ago
Strategies like intermittent fasting or diets that moderate what you eat rather than quantity are focused on the later aspect "strictly sticking to that diet". Because being strict is not sustainable, will power is limited and inconsistent, so wasting it on strategies that are hard to stick to is both futile and a waste of will power. Changing what and when you eat accounts for biology instead of just physics, because those variables have a huge impact on satiety.
The study has a minimum interval of 4 weeks, which does not take much will power. Not to mention the psychological impact of being part of a study.
freehorse|14 days ago
My experience with IF is that it makes it easier to schedule meals as well as to deal with whatever insatiety feelings come from reducing calories, and this made it easier for me to stay with IF diet than with other diets. I have read research where adherence is significantly higher in IF groups, other where it is lower. Essentially, adherence is firstmost about what works for a specific person. If the diet logistics don't work for you personally, it matters little what statistics say. The point (of any diet for weight loss/management) is always to reduce/control calories intake.
TGower|14 days ago
izzydata|14 days ago
If they had their test subjects eat the same amount to see if intermittent fasting metabolized food better then it seems obvious that there would be little to no difference.
thefz|14 days ago
cheema33|14 days ago
My personal experience is quite the opposite. In fact, this is the first time I have heard anybody claim that intermittent fasting, when done correctly, does not make you lose weight. Sounds like a study done by people who sell weight-loss drugs or meals.
Intermittent fasting is one of the more reliable ways to lose weight.
bulbar|14 days ago
Methods like intermittent fasting work by providing a framework that makes it easier for people to achieve that.
FatherOfCurses|14 days ago
That's not how data works.
unstatusthequo|14 days ago
What really accelerated weight loss for me was extremely rigid ketogenesis. Felt amazingly sharp and dialed in every morning, slept well, shredded pounds.
groos|14 days ago
There is one difference between Ramadan fasting and modern intermittent fasting: Ramadan fasts are 'dry' fasts no water is imbibed and the alimentary canal stays completely unstimulated for long periods of time.
bulbar|14 days ago
However, there's more than weight. I wonder if Ramadan has a lasting impact on blood sugar stability, for example.
empressplay|14 days ago
* I only eat one meal a day (supper). It's usually a very large meal, very high in lean protein.
* I avoid sugars and starches of all kinds and minimize other carbs (fruit, root veg, grains).
* After eating, I do 30 minutes on the treadmill.
For a middle-aged woman (a category which finds it particularly hard to lose weight) this has worked rather well. I can eat as much meat, (non-root) veg, dairy and soy as I want and I just keep losing weight.
So no, calorie restriction isn't the 'only way'.
kadabra9|14 days ago
It's very difficult to not be in a calorie deficit when you only eat once a day and are consistently active.
ranger_danger|14 days ago
Unless you have tested this, I find it hard to believe that this isn't really just a caloric deficit compared to whatever you were doing before losing weight, assuming the same activity level.
apt-apt-apt-apt|14 days ago
You restrict calories to one meal where you can't possibly eat 2000 calories at once with the ingredients.
Exercise + starting off at a high weight helps further.
skystarman|14 days ago
jdlyga|14 days ago
eska|14 days ago
Not a good sign for a meta study. When you average garbage you still get garbage.
As for my personal experience, I looked at scientific papers 5 years ago (no, intermittent fasting isn’t some new social media fad). The consensus back then was that it only slightly increases the speed at which one loses weight, but it helps significantly with adherence to a diet. This was a game changer for me too. With just attempts to control my caloric deficit I failed because I ended up snacking. With intermittent fasting (the strict variant of only eating once after work in my case) I simply had no appetite from the morning until my meal. I also didn’t have cravings before sleep.
ASalazarMX|14 days ago
This is my experience as well. IF didn't teach me how or what o eat, it taught me not to snack after the last meal of the day, and after losing around 10% of my weight (still obesity grade II), the weight-loss effect was lost. It didn't work for long-term weight loss, it just established a new equilibrium. Also, there's a bounce back if you stop it.
Currently, I'm on Mounjaro (diabetes type II likely caused by obesity and genetics), and IF meshes wonderfully with it, since mounjaro forces you to eat less or feel miserable. So far I've reached obesity grade I (aka plain obesity), and the effect has been very consistent over time, no new equilibrium reached yet.
So, for me, IF is not for weight loss, but it helps if you combine it with a proven method for weight loss.
hamdingers|14 days ago
Any framework that causes an overwieght person to genuinely pay attention to what they eat will have a weight loss impact, because all you have to do to lose weight is eat less. The wide variety of dieting techniques are a good thing because it maximizes the likelihood that any individual will find a framework that induces them to pay attention to their eating habits.
I've gone through many weight loss cycles using various techniques including OMAD. Eating once a day changes your relationship with food, and disrupting that relationship is a thousand times more important than whatever obscure biological processes the fitness gurus suppose are in play.
mh2266|14 days ago
I mostly ride bikes for exercise and need fuel at least every hour on a ride or else I will bonk out. My output is 500kcal/hour based on power meter, a 4 hour ride would be 2000kcal, it's not doable without some food intake.
zelda420|14 days ago
I also love weightlifting while being fasted. One meal end of day for me has put me in the best shape I ever have in 36 years. So much that I actually took up running haha.
haxel|14 days ago
Then I could wake up, ride hard for hours (hilly terrain), and feel no need to eat until the afternoon.
pandaman|14 days ago
tonyedgecombe|14 days ago
j45|14 days ago
Also, assertions in support of consumption should be reviewed to make sure it's not put forward into media and study by consumptionists.
codingbot3000|14 days ago
The main benefits of intermittent fasting are not in weight loss, but:
- Give your bowels the time to run the "cleaning program" (rumbling) - Reduce inflammation
Analemma_|14 days ago
Fire-Dragon-DoL|14 days ago
The big deal for me is not eating stuff with flour (starch?) or sugar.
I already eat healthy, although I switched from chicken to a full protein tofu that's low on calories and that has been a blessing for protein intake (along with egg white). I can eat 60g of protein at lunch in about 350 calories.
That gives me everything I need for the gym.
My snack is apple with a teaspoon of pure pistachio butter, which calms down my desire for sweets (I love pistachio)
pif|14 days ago
bob1029|14 days ago
8 hours is not a short window. I'm pretty sure Golden Corral will kick you out somewhere around hour #3.
Steven420|14 days ago
exabrial|14 days ago
That being said, it is an extraordinarily difficult way losing weight and probably is not sustainable long term.
unknown|14 days ago
[deleted]
xracy|14 days ago
The rest is just all new "fad diets" that cycle every 3 years as people go through the cycle of trying them, seeing results, failing to maintain them "forever" (which is what they'd have to do), and then putting the weight back on.
Every single diet has this problem (Even GLP-1s from what I have seen). The human body seems to have some mechanism by which it attempts to maintain it's current weight. But we all continue to be incredibly prone to "this new fad diet actually works!"
JohnnyLarue|14 days ago
[deleted]
rationalfaith|14 days ago
[deleted]
imadierich|14 days ago
[deleted]