Intermittent fasting doesn’t help you lose weight, UCSF study suggests(cnbc.com)
cnbc.com
Intermittent fasting doesn’t help you lose weight, UCSF study suggests
https://www.cnbc.com/2020/09/28/intermittent-fasting-doesnt-help-weight-loss-ucsf-study.html
34 comments
I agree to disagree which that headline. IF helps you to loose weight because it helps you to actually take in less calories.
I think it's basically a combination of two things:
1. It's really difficult to break out of that viscous high blood sugar -> Insulin -> felling hungry cycle using pure will power because it's really strong and it most of the time wins in the long run. Our typical high glucose western diet makes this even harder. (Intermittent) Fasting drastically puts the breaks in, anecdotally it can be very hard at the beginning but for many success arrives before willpower is depleted.
2. IF fasting is basically changing your eating habits while not changing your eating habits. Skipping a meal or two is easy (all you have to do is literally nothing) compared to making sure getting the "right" kind of meal in the "right" amount 3+ times a day is a constant effort both psychologically and depending on your daily routine even logistically. Also there is no feeling of missing out on things you like because you don't have to, you just delay them for a couple of hours.
// edit:
To add to that: In itself it's an interesting finding that there seems no additional weight loss effect by the fasting itself but the framing of this in the media (just to gain some attention) is really, really terrible in my opinion. It can turn people away from trying a weight loss technique which for many who failed and failed again with trying "simple" calorie reduction finally leads to success.
I think it's basically a combination of two things:
1. It's really difficult to break out of that viscous high blood sugar -> Insulin -> felling hungry cycle using pure will power because it's really strong and it most of the time wins in the long run. Our typical high glucose western diet makes this even harder. (Intermittent) Fasting drastically puts the breaks in, anecdotally it can be very hard at the beginning but for many success arrives before willpower is depleted.
2. IF fasting is basically changing your eating habits while not changing your eating habits. Skipping a meal or two is easy (all you have to do is literally nothing) compared to making sure getting the "right" kind of meal in the "right" amount 3+ times a day is a constant effort both psychologically and depending on your daily routine even logistically. Also there is no feeling of missing out on things you like because you don't have to, you just delay them for a couple of hours.
// edit:
To add to that: In itself it's an interesting finding that there seems no additional weight loss effect by the fasting itself but the framing of this in the media (just to gain some attention) is really, really terrible in my opinion. It can turn people away from trying a weight loss technique which for many who failed and failed again with trying "simple" calorie reduction finally leads to success.
> In Silicon Valley, entrepreneur Kevin Rose launched an app called Rise to help people monitor their fasts
The app is called Zero.
From the actual results of the study (CMT is consistent meal timing, TRE is time restricted eating aka intermittent fasting):
> There was a significant decrease in weight in the TRE group (−0.94 kg; 95% CI, −1.68 kg to −0.20 kg; P = .01) and a nonsignificant decrease in weight in the CMT group (−0.68 kg; 95% CI, −1.41 kg to 0.05 kg; P = .07). Importantly, there was no significant difference in weight change between groups (−0.26 kg; 95% CI, −1.30 kg to 0.78 kg; P = .63)
Both groups lost weight, the IF group lost more but the difference between the groups is not significant. Not quite what the title or article say. It would be good to see the actual dataset.
The app is called Zero.
From the actual results of the study (CMT is consistent meal timing, TRE is time restricted eating aka intermittent fasting):
> There was a significant decrease in weight in the TRE group (−0.94 kg; 95% CI, −1.68 kg to −0.20 kg; P = .01) and a nonsignificant decrease in weight in the CMT group (−0.68 kg; 95% CI, −1.41 kg to 0.05 kg; P = .07). Importantly, there was no significant difference in weight change between groups (−0.26 kg; 95% CI, −1.30 kg to 0.78 kg; P = .63)
Both groups lost weight, the IF group lost more but the difference between the groups is not significant. Not quite what the title or article say. It would be good to see the actual dataset.
The effect for this experiment is like too small to be significant.
Either the study should have been longer or there should have been more participants. The data seems to suggest there being an effect albeit a small one.
The interpretation of the result in the article seems to miss the point of what not meeting significance means... as is common in reports of scientific studies in mass media.
Either the study should have been longer or there should have been more participants. The data seems to suggest there being an effect albeit a small one.
The interpretation of the result in the article seems to miss the point of what not meeting significance means... as is common in reports of scientific studies in mass media.
I lost 10 kg after two months of doing 18 hour periods of fasting.
I’ve tried other diets and this one has been the only maintainable one. My body does not feel hunger at night anymore.
The success of going for long streaks of days has greatly motivated me of eating healthier, with less carbs, no snacking and more water.
So probably the fasting itself was not the direct but indirect cause of the lost.
I sometimes do eat at night, socially, but i always find it easy to go back to the fasting.
I’ve tried other diets and this one has been the only maintainable one. My body does not feel hunger at night anymore.
The success of going for long streaks of days has greatly motivated me of eating healthier, with less carbs, no snacking and more water.
So probably the fasting itself was not the direct but indirect cause of the lost.
I sometimes do eat at night, socially, but i always find it easy to go back to the fasting.
It definitely did work for me. I've always exercised and eaten healthy food but haven't found any other way to stay at a comfortable weight all of the time.
Initially I didn't eat until noon for a few months. I went from 165 pounds to 135 and lost some strength. (I'm male and 5'6" tall). When I switched to eating at 10:30 or 11:00, I went back up to 145 and am about as strong as I was at 165. I've now stayed within about 4 pounds of 145 for a whole year, which is unprecedented for me. I'm mostly vegan but make a point of getting 20 grams of protein per meal and of eating soon after exercising. I don't have a cutoff time at night, I eat late if I'm hungry.
Initially I didn't eat until noon for a few months. I went from 165 pounds to 135 and lost some strength. (I'm male and 5'6" tall). When I switched to eating at 10:30 or 11:00, I went back up to 145 and am about as strong as I was at 165. I've now stayed within about 4 pounds of 145 for a whole year, which is unprecedented for me. I'm mostly vegan but make a point of getting 20 grams of protein per meal and of eating soon after exercising. I don't have a cutoff time at night, I eat late if I'm hungry.
I've lost almost 20 lb so far. I eat between 11 am and 7 pm, and on one day a week I only eat one meal (dinner). The first month was tough, and I overate during my eating windows.
I did calorie tracking many times (sometimes successfully), but IF is so much less of a mental load. It addresses the core issue: appetite. After a month, I no longer want larger portions. I no longer want to snack after dinner.
I did calorie tracking many times (sometimes successfully), but IF is so much less of a mental load. It addresses the core issue: appetite. After a month, I no longer want larger portions. I no longer want to snack after dinner.
Can someone link to actual study? IF is hunger management strategy, if they tested X kcal IF vs X X kcal normal diet, I would not expect any difference, non-IF would just feel more hungry.
But besides psychological effects hard to measure, IF has also some obviously true benefits like time savings from less cooking, or better teeth.
But besides psychological effects hard to measure, IF has also some obviously true benefits like time savings from less cooking, or better teeth.
Didn't work for me. As an added bonus, ever since I stopped I get extremely tired after eating.
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sure.. I am IF atm, I just dont eat breakfast I eat only between 11am and 8pm only.
granted, i also eat smaller meals, I dont add sugar to my drinks anymore and I cycle for 30-60 mins a day every other day. I'm down 13kg since December and through the covid winter (im southern hemi) I managed to maintain that steady weight despite not riding more than once a week.
It all adds up. eat fewer calories and exercise and you'll lose weight.
but yeah I dont think there is any "magic formulae" to IF. Its just calorie restriction.
granted, i also eat smaller meals, I dont add sugar to my drinks anymore and I cycle for 30-60 mins a day every other day. I'm down 13kg since December and through the covid winter (im southern hemi) I managed to maintain that steady weight despite not riding more than once a week.
It all adds up. eat fewer calories and exercise and you'll lose weight.
but yeah I dont think there is any "magic formulae" to IF. Its just calorie restriction.
Diet research is mostly psychology. The biology is reasonably well understood; as you say, calorie reduction and exercise.
But both of those things are uncomfortable, and it's hard to get people to stick with it consistently. You can feel bad all week and still lose just one pound, an amount swamped by the normal daily variation in weight. People often give up or fail to follow the program, especially after the first week.
So pretty much all diet research is really about getting people to stick with the program rather than the nutrition in itself. The nutrition isn't irrelevant: a good diet can make you feel less uncomfortable than you might. Beyond that, it's about whatever program gives you the mental tools to deal with it.
But both of those things are uncomfortable, and it's hard to get people to stick with it consistently. You can feel bad all week and still lose just one pound, an amount swamped by the normal daily variation in weight. People often give up or fail to follow the program, especially after the first week.
So pretty much all diet research is really about getting people to stick with the program rather than the nutrition in itself. The nutrition isn't irrelevant: a good diet can make you feel less uncomfortable than you might. Beyond that, it's about whatever program gives you the mental tools to deal with it.
Anecdote, I’m down to 190lbs from nearly 230 about 4 months ago and IF has been an amazing tool to aid me in reduced caloric intake.
Honestly I think just having a routine was a big help but eliminating the time (after 8PM for me) that I’d most frequently snack on junk food made a huge difference.
For anyone looking for an iOS app to help track, fast habit is what I use and gladly paid the one time upgrade price. It has a few bugs related to adjusting inputs that annoy me but overall the app does help. In my case I think the biggest benefit to tracking the cycles is the constant commitments involved in “checking in”.
YMMV but for me, having a routine and making commitments were big factors in getting me to stick to the plan. I still eat some junk food to stay sane (took my family out for ice cream just last weekend) but generally I find it easier to pass on unhealthy food when I’m able to understand the disruption it can have on the progress I’m already enjoying.
TLDR: it works for me and feels sustainable, if you’ve struggled with weight loss then I’d suggest at least trying a few weeks.
Honestly I think just having a routine was a big help but eliminating the time (after 8PM for me) that I’d most frequently snack on junk food made a huge difference.
For anyone looking for an iOS app to help track, fast habit is what I use and gladly paid the one time upgrade price. It has a few bugs related to adjusting inputs that annoy me but overall the app does help. In my case I think the biggest benefit to tracking the cycles is the constant commitments involved in “checking in”.
YMMV but for me, having a routine and making commitments were big factors in getting me to stick to the plan. I still eat some junk food to stay sane (took my family out for ice cream just last weekend) but generally I find it easier to pass on unhealthy food when I’m able to understand the disruption it can have on the progress I’m already enjoying.
TLDR: it works for me and feels sustainable, if you’ve struggled with weight loss then I’d suggest at least trying a few weeks.
...in mice.
IF migi be a good took for some to help lower their calories but weight loss will always be dependent on calories out > calories in
This has been pretty thoroughly debunked as an over simplification. Hormones play a large role in weight loss. Hormones get out of whack with lack of sleep, poor food, too much alcohol, being lethargic, not getting enough sun, depression, anxiety, etc. I feel like I just described the many Americans.
BS. The human body obeys the laws of physics
Yeah, hence why this is an oversimplification, not false. Yes weight loss/gain is by definition the difference between calories in vs calories out, yet this simple definition makes it seem like losing weight should be as simple as a) reducing calories in, or b) increasing calories out, when in actuality reducing calories in may reduce calories out by the same or even greater amounts. It turns out these two variables are not independent, but instead connected by an extremely complex network of factors.
So yes, for many people, framing weight-loss as calories in vs calories out is a dramatic oversimplification.
So yes, for many people, framing weight-loss as calories in vs calories out is a dramatic oversimplification.
It is not helpful. There are too many variables in practice.
Trivial example: milk -- different effect depending on genes.
I dont even know how this is a rebuttal.
The body does not have the capability to create mass out of nothing. If you consume fewer calories than the body uses, you will lose weight. It literally doesn't matter what you eat as long as Calories In < Calories Out
Losing weight on the Fast Food Diet https://newsfeed.time.com/2014/01/05/teacher-loses-37-pounds...
Twinkie Diet https://www.cnn.com/2010/HEALTH/11/08/twinkie.diet.professor...
Beer Diet https://www.menshealth.com/weight-loss/a19532411/the-beer-di...
The body does not have the capability to create mass out of nothing. If you consume fewer calories than the body uses, you will lose weight. It literally doesn't matter what you eat as long as Calories In < Calories Out
Losing weight on the Fast Food Diet https://newsfeed.time.com/2014/01/05/teacher-loses-37-pounds...
Twinkie Diet https://www.cnn.com/2010/HEALTH/11/08/twinkie.diet.professor...
Beer Diet https://www.menshealth.com/weight-loss/a19532411/the-beer-di...
> The body does not have the capability to create mass out of nothing.
A human body is not an antimatter reactor. It expels mass constantly.
It's obviously thermodynamically possible to get less energy out of a piece of food simply by shitting out slightly more of it.
A human body is not an antimatter reactor. It expels mass constantly.
It's obviously thermodynamically possible to get less energy out of a piece of food simply by shitting out slightly more of it.
Yes, but a human body is not a bomb calorimeter. It doesn't perfectly combust everything that goes into the mouth.
"A battery will discharge if the outgoing current is less than the incoming current"
"Yeah, but the current controller won't perfectly convert the incoming electricity to a state usable by the battery"
Okay, so? What is the actual argument here?
"Yeah, but the current controller won't perfectly convert the incoming electricity to a state usable by the battery"
Okay, so? What is the actual argument here?
There are far more variables that affect how much energy a human body can get out of a piece of food than affect how much energy you will get out of a battery.
If you define "calories in" as "how much the person actually metabolized from the food they ate", then "calories in - calories out" will obviously determine their weight, but you can't actually measure calories in using that definition, so it's a useless definition.
For dietary purposes, the definition people are using is the number on the packet of food they ate, which there is obviously no law of thermodynamics requiring that it perfectly match their change in weight.
If you define "calories in" as "how much the person actually metabolized from the food they ate", then "calories in - calories out" will obviously determine their weight, but you can't actually measure calories in using that definition, so it's a useless definition.
For dietary purposes, the definition people are using is the number on the packet of food they ate, which there is obviously no law of thermodynamics requiring that it perfectly match their change in weight.
You will gain weight if you add more energy than you expend.
You are not immune to thermodynamics.
What you're describing are things that reduce the body's energy expenditure. Buy making it think it's in high cortisol survival mode.
But even then you can still lose weight if you're eating less than you're using.
You are not immune to thermodynamics.
What you're describing are things that reduce the body's energy expenditure. Buy making it think it's in high cortisol survival mode.
But even then you can still lose weight if you're eating less than you're using.
> You will gain weight if you add more energy than you expend. You are not immune to thermodynamics.
Do you honestly believe that the only way that a body can lose mass is by burning it off?
That belief shouldn't stand up to even the most cursory examination. You probably have an entire room in your house dedicated to another way of losing mass.
Do you honestly believe that the only way that a body can lose mass is by burning it off?
That belief shouldn't stand up to even the most cursory examination. You probably have an entire room in your house dedicated to another way of losing mass.
Okay, allow me to be hyper technical.
You body will hold excess energy in it's fat tissue if you consume more energy via food than you expend through metabolic active.
If you consume less energy via food than you are expending through metabolic activity, your body will convert fat tissue into the molecules it needs to meet it's energy needs.
You don't just shit the pounds off.
You body will hold excess energy in it's fat tissue if you consume more energy via food than you expend through metabolic active.
If you consume less energy via food than you are expending through metabolic activity, your body will convert fat tissue into the molecules it needs to meet it's energy needs.
You don't just shit the pounds off.
It's obviously thermodynamically possible for your body to be more or less efficient at metabolizing energy from the food you consume. The remainder will be excreted.
Someone who is lactose tolerant will gain more weight from a glass of milk than someone who is lactose intolerant because they are capable of getting energy from the lactose. The person who is lactose intolerant literally will shit those future pounds off.
Someone who is lactose tolerant will gain more weight from a glass of milk than someone who is lactose intolerant because they are capable of getting energy from the lactose. The person who is lactose intolerant literally will shit those future pounds off.
If something helps you eat less calories through a single day, it does have a potential in aiding weight loss.
Loosing weight, and keeping it off, is not only about eating less, but also about doing it in a way which is effortless. If you keep struggling to eat less, you're gonna have a bad time loosing weight and keeping it off.
Anecdotally, I effortlessly consume much fewer calories throughout the day if I delay my first meal to 13:00 (I usual get up around 8.00). That is to say, it's much easier for me to delay breakfast, than to start fasting only after e.g. 16.00 (because then I'm hungry when trying to fall asleep, and I end up eating right before going to sleep just to be able to fall asleep)
On top of that, eating fewer, but larger, meals also helps me eat less throughout the day. It's very easy to overload on calories by snacking. Also, with snacking, you keep your blood sugar high, which makes you hungry, which makes you snack more.
By having longer breaks between meals, you not only eat less, you do so with very little effort.