8 ms·

RCT of Intermittent Fasting

50 points by joshgel 6y ago

hprotagonist 6y ago
i have no dog in this fight, but it worth noting that a n of 116 likely has pretty low statistical power.
- joshgel 6y ago
  ehhh, really depends on what effect size you are looking for. presumably you would want to see a 10% effect size or more. (detecting that intermittent fasting caused 2 lbs more weight loss than CMT would be statistically valid, but not clinically that important)
riantogo 6y ago
Anecdote: I tried 16:8 intermittent fasting for a month (it wasn’t hard considering the lockdown situation). I gained 4lbs (156lbs to 160lbs). No claims are being made of mine being a proper experiment. Just sharing the observation. I generally don’t focus on weight. I did not do it to lose weight. My best guess is that my overall calorie intake went up as I fit all meals in that 8hr window.
- shock 6y ago
  Yes, in an 8h window you can certainly eat more calories than you burn if you sit on your arse all day.
JohnCohorn 6y ago
These people were significantly overweight, from almost obese to morbidly obese(by BMI). From such a starting condition initial weight loss can be extremely rapid, yet after 12 weeks they lost only .94 kg?
- arcticbull 6y ago
  This is a common source of misunderstanding, so I think it's worth clearing up: Rapid initial weight-loss is usually just a loss of glycogen, the front-line starch form of energy storage in your body. For every gram of glycogen you clear out, 2-3 grams of water goes with it. As soon as you eat anything, all the water comes back instantly. That may be weight loss, but it's definitely not fat loss. The metabolic pyramid roughly goes Alcohol > Sugar > Glycogen > Fat >>> Protein. Useful protein is extremely strongly conserved by your body, especially when fasting. Makes sense right, without your muscles, you wouldn't be able to hunt down and kill your next meal. Fat loss when totally fasted happens basically at a rate of your BMR, which goes up a bit when fasted. This is due to an increase in noradrenalin in the fasted state. Your BMR is roughly proportional to your body weight. A pound of fat contains 3500 calories. Your BMR is roughly ~2000 kcal per day for an average human, plus a bit more when fasted. This means when totally fasted you will lose roughly 2/3 of a pound of fat per day. That rate remains pretty consistent throughout your weight loss regimen. Over 12 weeks, they lost 2 pounds, or 7000kcal. That's a daily caloric deficit of 100kcal. Sounds like they weren't really on much of a diet.
  - dgacmu 6y ago
    Which still leaves the GPs question - the subjects averaged a 90 calorie per day deficit. (.94 x 2.2 x 3500 % (12*7)). That's fairly slow weight loss.
    - arcticbull 6y ago
      Indeed.
  - JohnCohorn 6y ago
    I’m very familiar with this having recently lost exactly 2lbs per week for many weeks to hit a 35lb total. At least in my experience it really is much easier to lose weight initially. Not sure if there are studies on this or just anecdotes. When I was borderline obese, losing weight was simply a matter of being vaguely mindful about “eating better”. After I lost a decent amount that way losing more took deliberate effort and tracking calories. The people in the study didn’t even lose the weight you would expect from the effect of losing glycogen and water retention.
magneticnorth 6y ago
Conclusion: "Time-restricted eating, in the absence of other interventions, is not more effective in weight loss than eating throughout the day." It is a pet peeve when a failure to reject the null hypothesis is reported (in confident language) as a confirmation of the null hypothesis. However, I do appreciate how clear the results section is in breaking down exactly what they did measure: both groups lost weight, and the time-restricted group lost more but not significantly more in the overall study.
- darkerside 6y ago
  I agree with you, especially considering news outlets will take this conclusion and report it in the absence of contextual data, and that it makes an incorrect claim.
aoeusnth1 6y ago
n=116 is not high power enough to make a strong claim that it is not more effective, only that they were unable to prove that it was effective.
- joshgel 6y ago
  as i said lower down: "ehhh, really depends on what effect size you are looking for. presumably you would want to see a 10% effect size or more. (detecting that intermittent fasting caused 2 lbs more weight loss than CMT would be statistically valid, but not clinically that important)" power depends not just on n but also on the expected difference between the means (and the standard deviation of the mean)
samatman 6y ago
This compares 3 'structured' meals a day, to ad libidum eating over an 8 hour window. ...what's the point? why would anyone conduct this study, how does precisely three meals with pre-calculated caloric value relate in any way to eating as much as you want in 8 hours.
- j4nt4b 6y ago
  Garbage in, garbage out. The iron law of nutrition has been conclusively proven to apply to nutritional science itself.
adewinter 6y ago
There doesn't seem to be any information regarding adherence to the protocol. Did the participants manage to keep to either strictly Intermittent Fasting or a stern 3-meals-per-day-and-nothing-else program? Considering that the participants were all "Overweight" or "Obese", implying that the participants have historical issues with portion/calorie-intake control, that seems like a pretty important point to ignore.
- joshgel 6y ago
  Certainly hard to measure, but Figure 2A certainly looks like an adherence chart. Regardless, in RCTs we usually consider a 'intention to treat' analysis gold-standard. That means that since you are assigning an intervention in the real world, even if someone drops out, you still consider them part of the intervention group, because the same thing will happen in the real world. You can also do a 'per protocol' analysis, which attempts to measure the impact of the intervention to those that adhered, but not as important...
  - adewinter 6y ago
    That's a fair point: if study subjects can't/won't adhere to the protocol why would we expect real world participants to do so? Either the study subjects adhered to the program and the results showed (little to) no improvement OR real people won't adhere to the program anyway and results will show (little to) no improvement.
    - deleted 6y ago
      [deleted]
  - p1necone 6y ago
    As an individual though I would certainly want to know about a treatment that would cure my condition, even if few people tend to stick with it.
TimSchumann 6y ago
As someone who's had Extensive experience with fasting, both intermittent and extended, I would hardly even consider this study 'Time Restricted Eating' much less fasting.
- arcticbull 6y ago
  Indeed. This is just eating lunch at noon and dinner any time before 8pm with unlimited snacks allowed in between. That's not much of an intermittent fasting regimen unless you're eating all the time.
- RandallBrown 6y ago
  Why isn't eating only between noon and 8pm time restricted eating? I thought that was one style of intermittent fasting.
  - arcticbull 6y ago
    I don't want to move the goalposts here because I think this is worth studying and I'm happy to see any studies being done at all. From my research, and I'm happy to dig up my sources: The longer you go between meals the more pronounced the effect. 16:8 with ad libitum eating is what a lot of people kinda do naturally if they skip breakfast. The longer you abstain the more pronounced metabolic changes you see. Human growth hormone levels triple over fasted period of, for instance, 5 days. Glucose levels fall off a cliff, and so do free fatty acids. [1] It's unclear that fasting for less than a day would yield similar effects. I think the idea that if you don't eat, you lose weight, is pretty well documented so it feels like all we can really take away from this study is 16:8 with all the food you can eat doesn't qualify. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC329619/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC329619/
    - vcxy 6y ago
      For a different point of view: I can't imagine being able to sustain restriction to 8 hours for more than a day. I've struggled with gaining weight my entire life, which is certainly not the norm, so I'm not really a central example of anything. The point about growth hormone is interesting. Im not sure if I'd be able to eat enough Calories in that time to survive, but if I were able to fit them all in to 8 hours, do you think someone who is under weight but doing consistent weight training would actually gain weight?
RobLach 6y ago
One group has 3 calorie restricted meals and another has an 8 hour window where they eat whatever amount they want.... Useless.
- j4nt4b 6y ago
  My jaw dropped when I read `ad libitum`. The single biggest impact that restricting the number of meals had for me was to decrease my appetite and increase my resilience to a baseline level of hunger. Telling chronically overweight/obese people to eat as much as they want during this kind of a trial subverts a golden opportunity to accustom the body to actually eating less food.
  - thesishelp 6y ago
    this is something in clinical research called the dichotomy between pragmatic and explanatory trials. RCTs like this aren't useless even though they don't specifically answer the question YOU expect to have answered, which is essentially: "controlling caloric intake, what impact does restricted meal windows have on weight gain/loss/other measured outcomes?" This is an explanatory question--it seeks to isolate a variable (meal timing) and explain it's impact on people. in contrast, the question the RCT is REALLY asking is essentially: "comparing ad libitum intermittent fasting (which is a very easy thing to suggest in a busy clinic) to a very expectably superior intervention like calorie tracking and restriction, does IF end up having some efficacy?" it's a different question--more realistic of an intervention to provide and monitor (because you don't monitor it at all really...)--and so ends up being perfectly valuable if you interpret it for what it is, assuming the rest of your critical appraisal of the paper passes muster.
markhalonen 6y ago
I do 16:8 to maintain weight. To lose weight, I'd do OMAD (One Meal A Day)
- antidaily 6y ago
  I didn't have much luck with OMAD. I lost very little and felt like I lost much more muscle than fat.
- mikevm 6y ago
  Never heard of OMAD before, but that sounds like a bad strategy. If anything, might as well do a PSMF for a short period of time.
GhostVII 6y ago
I think the fact that the time-restricted eating group did slightly better than the consistent meal timing group is actually pretty strong evidence that intermittent fasting is effective. At least for me, it is much easier to only eat during a certain time period than to hold to a 3 meal a day schedule, so the fact that the groups performed similarly shows a lot of the value of intermittent fasting - same results with simpler rules. Also I'm surprised that a 1% drop in body weight across ~100 participants gives statistically significant results - isn't that pretty well within daily fluctuation due to water intake? I would imagine most people who are trying to lose weight are aiming to lose more like 10% than 1%.
- URSpider94 6y ago
  This is a logical fallacy. They didn’t test against “eat whenever you want” as a baseline, so you can’t draw any conclusions about effectiveness. Also, as you point out, there was no significant weight loss in either cohort, meaning NEITHER is effective for weight loss, though that may be against a baseline of weight gain (we don’t know without the zero-intervention control).
  - kovach 6y ago
    From the study: (TRE = time-restricted eating) > There was a significant decrease in weight in the TRE (−0.94 kg; 95% CI, −1.68 to −0.20; P = .01)
    - URSpider94 6y ago
      Sorry, I was using "significant" in the non-scientific sense of the word. They proved with statistical significance that people lost weight, but the amount they lost (less than 1 kilo) is not medically or personally significant.
asimjalis 6y ago
What is RCT? This is not in the title of the linked article.
- skosch 6y ago
  https://en.wikipedia.org/wiki/Randomized_controlled_trial https://en.wikipedia.org/wiki/Randomized_controlled_trial
j4nt4b 6y ago
How does one fund such a terribly designed study in the first place? I too, have got a few bridges to sell...
itake 6y ago
_When_ you eat your food has never directly related to weight loss, but by restricting your eating window, it is easier psychologically to not exceed your calorie limits for a given day than trying to stay within the calorie limit, but eating whenever you want. I am curious if there is a study on if participants that use IF alongside calorie restrictive diet are able lose weight faster than people that don't fast.
- deleted 6y ago
  [deleted]
- bostonvaulter2 6y ago
  As well as checking if that is a more long-term sustainable diet
- kelnos 6y ago
  I'm curious about that as well. My girlfriend and I do 18:6 intermittent fasting (she's very strict about it while I'm... less so). We also get a decent amount of exercise, and while I don't count calories anymore, I do try to limit my calorie intake. That, plus shifting from eating out a lot to cooking nearly every day during COVID restrictions has caused me to lose 15-20 lbs. I'd tried intermittent fasting in the past, without making any dietary changes, and it never did anything. The only thing that's consistently allowed me to lose weight has been changing my diet. IF probably helps me, due to the psychological effect you mentioned.
- voisin 6y ago
  > _ When_ you eat your food has never directly related to weight loss I am not sure this is true. Insulin levels rise naturally just before waking, and apparently the same calories consumed at breakfast as at lunch has a different impact on fat accumulation. The general theme I keep coming across is that calories in, calories out is too simplistic and that weight loss is driven by hormones which fluctuate with the circadian cycle and _what_ you eat with respect to those calories.
  - itake 6y ago
p1necone 6y ago
From my reading it sounds like calories eaten were not controlled between the two groups? Surely the study would be much more useful if the groups consumed the same number of calories per week? If fasting results in wanting to eat less/more it's going to be completely unsurprising for that to result in more/less weight loss respectively, any weight loss due to the fasting itself, as opposed to standard calorie restriction is going to be difficult to extract from the data without a very large sample size.
- aidenn0 6y ago
  I thought it was fairly well established that most (all?) diets cause weight loss by inducing a calorie deficit?
  - p1necone 6y ago
    Proponents of intermittent fasting seem to think it's more than just calorie restriction having an effect. I would think it would be useful to isolate why the treatment works. Although I can also see why a clinical trial of a treatment would need to test the treatment as it would be applied in the real world, as opposed to a modified version intended to extract the why.
voisin 6y ago
I’d be interested to see the impact to insulin between both groups vs their baseline.
jl2718 6y ago
I did this for years, and, it was the easiest way to cut calories and get quite lean, but really not great for life in general. Now I have a revolutionary new diet: “Eat when you are hungry. Don’t eat when you are not hungry.” Also choose things that digest slowly. I am not nearly as lean as I was on IF, but I also think I was losing muscle, which is a lot harder to gain back than the fat was to lose. Also I don’t have anybody to impress anymore, so, don’t really care. Side note, using IF as a social excuse against eating is a lot easier than “I don’t feel like it”.
debayanin 6y ago
Isn't this supposed to be the conclusion? "In the in-person cohort (n = 50), there was a significant decrease in weight in the TRE group using the in-person weight measurements but not in the CMT group " ?

50 points by joshgel 6y ago

hprotagonist 6y ago

i have no dog in this fight, but it worth noting that a n of 116 likely has pretty low statistical power.

joshgel 6y ago
ehhh, really depends on what effect size you are looking for. presumably you would want to see a 10% effect size or more. (detecting that intermittent fasting caused 2 lbs more weight loss than CMT would be statistically valid, but not clinically that important)

riantogo 6y ago

Anecdote: I tried 16:8 intermittent fasting for a month (it wasn’t hard considering the lockdown situation). I gained 4lbs (156lbs to 160lbs). No claims are being made of mine being a proper experiment. Just sharing the observation. I generally don’t focus on weight. I did not do it to lose weight. My best guess is that my overall calorie intake went up as I fit all meals in that 8hr window.

shock 6y ago
Yes, in an 8h window you can certainly eat more calories than you burn if you sit on your arse all day.

JohnCohorn 6y ago

These people were significantly overweight, from almost obese to morbidly obese(by BMI). From such a starting condition initial weight loss can be extremely rapid, yet after 12 weeks they lost only .94 kg?

arcticbull 6y ago
This is a common source of misunderstanding, so I think it's worth clearing up: Rapid initial weight-loss is usually just a loss of glycogen, the front-line starch form of energy storage in your body. For every gram of glycogen you clear out, 2-3 grams of water goes with it. As soon as you eat anything, all the water comes back instantly. That may be weight loss, but it's definitely not fat loss. The metabolic pyramid roughly goes Alcohol > Sugar > Glycogen > Fat >>> Protein. Useful protein is extremely strongly conserved by your body, especially when fasting. Makes sense right, without your muscles, you wouldn't be able to hunt down and kill your next meal. Fat loss when totally fasted happens basically at a rate of your BMR, which goes up a bit when fasted. This is due to an increase in noradrenalin in the fasted state. Your BMR is roughly proportional to your body weight. A pound of fat contains 3500 calories. Your BMR is roughly ~2000 kcal per day for an average human, plus a bit more when fasted. This means when totally fasted you will lose roughly 2/3 of a pound of fat per day. That rate remains pretty consistent throughout your weight loss regimen. Over 12 weeks, they lost 2 pounds, or 7000kcal. That's a daily caloric deficit of 100kcal. Sounds like they weren't really on much of a diet.
- dgacmu 6y ago
  Which still leaves the GPs question - the subjects averaged a 90 calorie per day deficit. (.94 x 2.2 x 3500 % (12*7)). That's fairly slow weight loss.
  - arcticbull 6y ago
    Indeed.
- JohnCohorn 6y ago
  I’m very familiar with this having recently lost exactly 2lbs per week for many weeks to hit a 35lb total. At least in my experience it really is much easier to lose weight initially. Not sure if there are studies on this or just anecdotes. When I was borderline obese, losing weight was simply a matter of being vaguely mindful about “eating better”. After I lost a decent amount that way losing more took deliberate effort and tracking calories. The people in the study didn’t even lose the weight you would expect from the effect of losing glycogen and water retention.

magneticnorth 6y ago

Conclusion: "Time-restricted eating, in the absence of other interventions, is not more effective in weight loss than eating throughout the day." It is a pet peeve when a failure to reject the null hypothesis is reported (in confident language) as a confirmation of the null hypothesis. However, I do appreciate how clear the results section is in breaking down exactly what they did measure: both groups lost weight, and the time-restricted group lost more but not significantly more in the overall study.

darkerside 6y ago
I agree with you, especially considering news outlets will take this conclusion and report it in the absence of contextual data, and that it makes an incorrect claim.

aoeusnth1 6y ago

n=116 is not high power enough to make a strong claim that it is not more effective, only that they were unable to prove that it was effective.

joshgel 6y ago
as i said lower down: "ehhh, really depends on what effect size you are looking for. presumably you would want to see a 10% effect size or more. (detecting that intermittent fasting caused 2 lbs more weight loss than CMT would be statistically valid, but not clinically that important)" power depends not just on n but also on the expected difference between the means (and the standard deviation of the mean)

samatman 6y ago

This compares 3 'structured' meals a day, to ad libidum eating over an 8 hour window. ...what's the point? why would anyone conduct this study, how does precisely three meals with pre-calculated caloric value relate in any way to eating as much as you want in 8 hours.

j4nt4b 6y ago
Garbage in, garbage out. The iron law of nutrition has been conclusively proven to apply to nutritional science itself.

adewinter 6y ago

There doesn't seem to be any information regarding adherence to the protocol. Did the participants manage to keep to either strictly Intermittent Fasting or a stern 3-meals-per-day-and-nothing-else program? Considering that the participants were all "Overweight" or "Obese", implying that the participants have historical issues with portion/calorie-intake control, that seems like a pretty important point to ignore.

joshgel 6y ago
Certainly hard to measure, but Figure 2A certainly looks like an adherence chart. Regardless, in RCTs we usually consider a 'intention to treat' analysis gold-standard. That means that since you are assigning an intervention in the real world, even if someone drops out, you still consider them part of the intervention group, because the same thing will happen in the real world. You can also do a 'per protocol' analysis, which attempts to measure the impact of the intervention to those that adhered, but not as important...
- adewinter 6y ago
  That's a fair point: if study subjects can't/won't adhere to the protocol why would we expect real world participants to do so? Either the study subjects adhered to the program and the results showed (little to) no improvement OR real people won't adhere to the program anyway and results will show (little to) no improvement.
  - deleted 6y ago
    [deleted]
- p1necone 6y ago
  As an individual though I would certainly want to know about a treatment that would cure my condition, even if few people tend to stick with it.

TimSchumann 6y ago

As someone who's had Extensive experience with fasting, both intermittent and extended, I would hardly even consider this study 'Time Restricted Eating' much less fasting.

arcticbull 6y ago
Indeed. This is just eating lunch at noon and dinner any time before 8pm with unlimited snacks allowed in between. That's not much of an intermittent fasting regimen unless you're eating all the time.
RandallBrown 6y ago
Why isn't eating only between noon and 8pm time restricted eating? I thought that was one style of intermittent fasting.
- arcticbull 6y ago
  I don't want to move the goalposts here because I think this is worth studying and I'm happy to see any studies being done at all. From my research, and I'm happy to dig up my sources: The longer you go between meals the more pronounced the effect. 16:8 with ad libitum eating is what a lot of people kinda do naturally if they skip breakfast. The longer you abstain the more pronounced metabolic changes you see. Human growth hormone levels triple over fasted period of, for instance, 5 days. Glucose levels fall off a cliff, and so do free fatty acids. [1] It's unclear that fasting for less than a day would yield similar effects. I think the idea that if you don't eat, you lose weight, is pretty well documented so it feels like all we can really take away from this study is 16:8 with all the food you can eat doesn't qualify. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC329619/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC329619/
  - vcxy 6y ago
    For a different point of view: I can't imagine being able to sustain restriction to 8 hours for more than a day. I've struggled with gaining weight my entire life, which is certainly not the norm, so I'm not really a central example of anything. The point about growth hormone is interesting. Im not sure if I'd be able to eat enough Calories in that time to survive, but if I were able to fit them all in to 8 hours, do you think someone who is under weight but doing consistent weight training would actually gain weight?

RobLach 6y ago

One group has 3 calorie restricted meals and another has an 8 hour window where they eat whatever amount they want.... Useless.

j4nt4b 6y ago
My jaw dropped when I read `ad libitum`. The single biggest impact that restricting the number of meals had for me was to decrease my appetite and increase my resilience to a baseline level of hunger. Telling chronically overweight/obese people to eat as much as they want during this kind of a trial subverts a golden opportunity to accustom the body to actually eating less food.
- thesishelp 6y ago
  this is something in clinical research called the dichotomy between pragmatic and explanatory trials. RCTs like this aren't useless even though they don't specifically answer the question YOU expect to have answered, which is essentially: "controlling caloric intake, what impact does restricted meal windows have on weight gain/loss/other measured outcomes?" This is an explanatory question--it seeks to isolate a variable (meal timing) and explain it's impact on people. in contrast, the question the RCT is REALLY asking is essentially: "comparing ad libitum intermittent fasting (which is a very easy thing to suggest in a busy clinic) to a very expectably superior intervention like calorie tracking and restriction, does IF end up having some efficacy?" it's a different question--more realistic of an intervention to provide and monitor (because you don't monitor it at all really...)--and so ends up being perfectly valuable if you interpret it for what it is, assuming the rest of your critical appraisal of the paper passes muster.

markhalonen 6y ago

I do 16:8 to maintain weight. To lose weight, I'd do OMAD (One Meal A Day)

antidaily 6y ago
I didn't have much luck with OMAD. I lost very little and felt like I lost much more muscle than fat.
mikevm 6y ago
Never heard of OMAD before, but that sounds like a bad strategy. If anything, might as well do a PSMF for a short period of time.

GhostVII 6y ago

I think the fact that the time-restricted eating group did slightly better than the consistent meal timing group is actually pretty strong evidence that intermittent fasting is effective. At least for me, it is much easier to only eat during a certain time period than to hold to a 3 meal a day schedule, so the fact that the groups performed similarly shows a lot of the value of intermittent fasting - same results with simpler rules. Also I'm surprised that a 1% drop in body weight across ~100 participants gives statistically significant results - isn't that pretty well within daily fluctuation due to water intake? I would imagine most people who are trying to lose weight are aiming to lose more like 10% than 1%.

URSpider94 6y ago
This is a logical fallacy. They didn’t test against “eat whenever you want” as a baseline, so you can’t draw any conclusions about effectiveness. Also, as you point out, there was no significant weight loss in either cohort, meaning NEITHER is effective for weight loss, though that may be against a baseline of weight gain (we don’t know without the zero-intervention control).
- kovach 6y ago
  From the study: (TRE = time-restricted eating) > There was a significant decrease in weight in the TRE (−0.94 kg; 95% CI, −1.68 to −0.20; P = .01)
  - URSpider94 6y ago
    Sorry, I was using "significant" in the non-scientific sense of the word. They proved with statistical significance that people lost weight, but the amount they lost (less than 1 kilo) is not medically or personally significant.

asimjalis 6y ago

What is RCT? This is not in the title of the linked article.

skosch 6y ago
https://en.wikipedia.org/wiki/Randomized_controlled_trial https://en.wikipedia.org/wiki/Randomized_controlled_trial

j4nt4b 6y ago

How does one fund such a terribly designed study in the first place? I too, have got a few bridges to sell...

itake 6y ago

_When_ you eat your food has never directly related to weight loss, but by restricting your eating window, it is easier psychologically to not exceed your calorie limits for a given day than trying to stay within the calorie limit, but eating whenever you want. I am curious if there is a study on if participants that use IF alongside calorie restrictive diet are able lose weight faster than people that don't fast.

deleted 6y ago
[deleted]
bostonvaulter2 6y ago
As well as checking if that is a more long-term sustainable diet
kelnos 6y ago
I'm curious about that as well. My girlfriend and I do 18:6 intermittent fasting (she's very strict about it while I'm... less so). We also get a decent amount of exercise, and while I don't count calories anymore, I do try to limit my calorie intake. That, plus shifting from eating out a lot to cooking nearly every day during COVID restrictions has caused me to lose 15-20 lbs. I'd tried intermittent fasting in the past, without making any dietary changes, and it never did anything. The only thing that's consistently allowed me to lose weight has been changing my diet. IF probably helps me, due to the psychological effect you mentioned.
voisin 6y ago
> _ When_ you eat your food has never directly related to weight loss I am not sure this is true. Insulin levels rise naturally just before waking, and apparently the same calories consumed at breakfast as at lunch has a different impact on fat accumulation. The general theme I keep coming across is that calories in, calories out is too simplistic and that weight loss is driven by hormones which fluctuate with the circadian cycle and _what_ you eat with respect to those calories.
- itake 6y ago

p1necone 6y ago

From my reading it sounds like calories eaten were not controlled between the two groups? Surely the study would be much more useful if the groups consumed the same number of calories per week? If fasting results in wanting to eat less/more it's going to be completely unsurprising for that to result in more/less weight loss respectively, any weight loss due to the fasting itself, as opposed to standard calorie restriction is going to be difficult to extract from the data without a very large sample size.

aidenn0 6y ago
I thought it was fairly well established that most (all?) diets cause weight loss by inducing a calorie deficit?
- p1necone 6y ago
  Proponents of intermittent fasting seem to think it's more than just calorie restriction having an effect. I would think it would be useful to isolate why the treatment works. Although I can also see why a clinical trial of a treatment would need to test the treatment as it would be applied in the real world, as opposed to a modified version intended to extract the why.

voisin 6y ago

I’d be interested to see the impact to insulin between both groups vs their baseline.

jl2718 6y ago

I did this for years, and, it was the easiest way to cut calories and get quite lean, but really not great for life in general. Now I have a revolutionary new diet: “Eat when you are hungry. Don’t eat when you are not hungry.” Also choose things that digest slowly. I am not nearly as lean as I was on IF, but I also think I was losing muscle, which is a lot harder to gain back than the fat was to lose. Also I don’t have anybody to impress anymore, so, don’t really care. Side note, using IF as a social excuse against eating is a lot easier than “I don’t feel like it”.

debayanin 6y ago

Isn't this supposed to be the conclusion? "In the in-person cohort (n = 50), there was a significant decrease in weight in the TRE group using the in-person weight measurements but not in the CMT group " ?