Writes Gina Kolata (in the NYT).
But now, a rigorous one-year study in which people followed a low-calorie diet between the hours of 8 a.m. and 4 p.m. or consumed the same number of calories anytime during the day has failed to find an effect. The bottom line, said Dr. Ethan Weiss, a diet researcher at the University of California, San Francisco: “There is no benefit to eating in a narrow window.”
It seems to me you could still say that by shortening your time period for eating, you might eat less.
The scientists also found no differences in such risk factors as blood glucose levels, sensitivity to insulin, blood lipids or blood pressure.
“These results indicate that caloric intake restriction explained most of the beneficial effects seen with the time-restricted eating regimen,” Dr. Weiss and his colleagues concluded.
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I am a "believer" that TRE works, but nobody I know of who seriously does it thinks you should have an 8 hour window to gorge. You eat within say a 4 hour window and the window should not be right before bed.
Duh. Same calories in, same calories out. same weight profile. I agree with Althouse. Shorter eating window and you might eat less food. It seems to work well for me. An easy "discipline" to maintain. I'm less inclined to eat desert every night if I have a Cinderella hour.
Ann said "It seems to me you could still say that by shortening your time period for eating, you might eat less."
That may or may not be generally true. However, that could never be concluded from this study, since the total number of calories consumed was held constant in both cases. There was not 'eating more' or 'eating less'; only the time period when food was consumed was allowed to vary... that was the point of the study.
8 am to 4 pm is not a restricted time frame. Try 12 pm to 4 pm. I don't know of anyone using intermittent fasting that recommends and 8 hour feeding window.
If you like Gina Kolatas,
And getting caught in the rain...
I'm sure that jokes been made a hundred times already, but I just had to get it out!
Intermittent fasting has never directly helped me lose weight. It does make restricting calories easier and appears to have an impact on my body composition, losing more fat than protein, and, perhaps, preventing loose skin when I lose larger amounts of weight.
Clearly it's better to keep the weight off, but I gain easily and recent medical treatments heavy in steroids caused me to pack weight on. Down a decent 26 pounds so far. Everybody's different, whatever works, at least if you don't do anything screwy that hurts your health.
“There is no benefit to eating in a narrow window.”
I don't think you should eat glass EVER.
Years ago I found a weird cookbook by two previously obese research scientists who decided to eat almost nothing all day, then eat whatever they wanted for one hour. Fried chicken, potatoes and gravy, wine, chocolate cake. The rest of the day it was 200 calories total or less. They said the reward hour made the rest of the day bearable, and they showed dramatic before and after photos.
But they had to sit at the dinner table to eat their large dinner like a regular meal and stop at precisely 60 minutes.
I don't have the book anymore, but I have a very early keto-like cookbook recommending a diet of cream, butter, eggs, cheese, all-day martinis, and fatty meats, but no carbohydrates(which had to be explained). The several-course menus would kill a person today, unless maybe that person was Joe Rogan.
"But now, a rigorous one-year study in which people followed a low-calorie diet between the hours of 8 a.m. and 4 p.m"
Seems a weird slot. I do 12-8. Basically skip breakfast.
Althouse: "It seems to me you could still say that by shortening your time period for eating, you might eat less."
Of course! I'm on a reduced calorie diet to lose weight, and it's easy to do when squeezing that consumption into 8 hours versus 16. You really are never that hungry. Most weeks I'm well under my target.
"found no differences in such risk factors as blood glucose levels"
I do.
It mindfulness is the answer.
Count calories, carbs, exercise, time, moons, starfish
Tracking something changes behavior. Schrodinger's cat.
>>It seems to me you could still say that by shortening your time period for eating, you might eat less.
I think that's a legit scenario.
A similar study came out several years ago, testing the hypothesis that people who ate late, like shortly before bed, would get fatter because they'd have this big calorie dump when they're asleep and not active; pretty much similar results.
I've tried the intermittent fasting idea and found very little benefit. Lowering overall caloric intake is the simple key to weight loss. Who would have guessed?
There is some data on metabolic benefits for fasting but those fasts are substantially longer than the 16 hour fasts that are "intermittent fasting" according the smart fasting crowd. I think you have to starve like a bad hunter in a hunter gatherer society for your body to make metabolic adaptations.
The one good thing I learned from intermittent fasting is what actual hunger feels like. It is very different from "time to eat" and "I'm bored" which seems to be what motivates most folks to eat.
The people I've read promoting intermittent fasting only emphasize weight loss as a result of the calorie reduction from eating fewer meals.
The people I've read who argue that the timing of your meal should encourage weight loss are the ones who say you should be eating all the time (not more calories, just more frequency). Their big idea is that if you fast, your body goes into famine mode, lowers your metabolism, and converts as many calories as it can to fat. But if you graze, your body anticipates regular food intake, stops trying to conserve energy, and raises your metabolism.
caloric intake restriction ..
here's gilbar's Super Secret, yet UTTERLY Successful diet plan; Consume Less Calories than you Use.
Do THAT; you'll Lose Weight.. Don't do that; you Won't
I've been doing intermittent fasting for almost 2 years, after struggling for a long time to lose 5 uncomfortable pounds. I don't eat from 11 p.m. until 3 p.m. It's worked well, but I think it IS mostly due to basically eliminating breakfast and lunch. (I have coffee in the morning, a snack after 3, and eat my one meal around 8 p.m.). I'm also a type 1 diabetic, so eat very low carb anyhow. I've successfully stayed around 112 lbs., and my blood pressure has gone down, too. It's worth a try if you have the discipline.
Having spent the last 4 months rigorously tracking my macronutrient intake and blood glucose levels (1,300+ glucose measurements), I am not surprised.
Calories count.
Althouse, your "might eat less” triggered my STEM soul to depths which I doubt your artistic soul is capable of understanding. That "might" epitomizes the unconscious observational bias that makes worthless many modern studies, much modern thought. I won't bore us all with my ranting on the subject, but note well the violence of feeling it awakens. Although, why you should care escapes me.
Ii can lose pounds (and it is very slowly at my age) when I limit food (except coffee+cream) between 6 hours each day and try to keep it fairly low carb.
Perhaps it is merely because if I eat food early in the day, I will eat all day long. It's easier to control w/in a short time period that throughout the day?
I dunno - but it's the only thing that works for me to lose - and maintain - weight.
It's always been about the calories. While simple in theory eating the same amount of calories as your base metabolism will maintain your weight. Eating less will result in losing weight. Doing that is far from easy, especially for an unending period of time. Being perpetually hungry is to say the least, unpleasant.
There is a mathematical equation: calories in minus calories out. If that's a positive number, you gain weight. Any advice which might seem to complicate that is wrong.
That leaves most of us struggling to figure out how to contain calories in. Fixing calories in is the problem, not something to assume is fixed.
For some people, containing the hours during which calories are allowed to be consumed is useful in containing calories per day.
This study is consistent with many of its type: They debunk something which nobody believed.
It was always the case that intermittent fasting, or time-limited eating, helps you lose weight by helping you eat less. It's not just that you're eating during fewer hours per day, it's that you're gaining control over hunger. When you do 24 hour fasts, as I do twice/week, you train your mind and body to adapt to that. This makes it easier to ignore hunger and eat mindfully.
While not statistically significant, the time restriction eaters lost about 4-pounds more after a year.
RESULTS
Of the total 139 participants who underwent randomization, 118 (84.9%) completed the 12-month follow-up visit. The mean weight loss from baseline at 12 months was −8.0 kg (95% confidence interval [CI], −9.6 to −6.4) in the time-restriction group and −6.3 kg (95% CI, −7.8 to −4.7) in the daily-calorie-restriction group. Changes in weight were not significantly different in the two groups at the 12-month assessment (net difference, −1.8 kg; 95% CI, −4.0 to 0.4; P=0.11). Results of analyses of waist circumferences, BMI, body fat, body lean mass, blood pressure, and metabolic risk factors were consistent with the results of the primary outcome. In addition, there were no substantial differences between the groups in the numbers of adverse events.
CONCLUSIONS
Among patients with obesity, a regimen of time-restricted eating was not more beneficial with regard to reduction in body weight, body fat, or metabolic risk factors than daily calorie restriction. (Funded by the National Key Research and Development Project [No. 2018YFA0800404] and others; ClinicalTrials.gov number, NCT03745612. opens in new tab.)
My sister just told me that was the key to restarting her weight loss- little that she needs to lose.
No one likes the boring truth. SOME HOW you have to get into a calorie deficit if you want to lose some meaningful amounts of weight (fat). Intermittent fasting, keto, plant-based or any other tools are just that, tools for helping someone to get into calorie deficit. This means eating fewer calories than you burn. Some methods may help you do it in a less miserable way. That's it. Sorry folks! ❤️
P.S. But every time we try to eat healthy and sensibly, along comes Christmas, Easter, summer, Friday, or Tuesday and ruins it for us.
I'm somewhat familiar with the claims made by intermittent fasting proponents. In summary, they claim that IF works for people who have been obese for a long period of time, where other diets have failed. So out of curiosity, I went to the abstract. https://www.nejm.org/doi/full/10.1056/NEJMoa2114833
Here's the findings:
"RESULTS
Of the total 139 participants who underwent randomization, 118 (84.9%) completed the 12-month follow-up visit. The mean weight loss from baseline at 12 months was −8.0 kg (95% confidence interval [CI], −9.6 to −6.4) in the time-restriction group and −6.3 kg (95% CI, −7.8 to −4.7) in the daily-calorie-restriction group. Changes in weight were not significantly different in the two groups at the 12-month assessment (net difference, −1.8 kg; 95% CI, −4.0 to 0.4; P=0.11). Results of analyses of waist circumferences, BMI, body fat, body lean mass, blood pressure, and metabolic risk factors were consistent with the results of the primary outcome. In addition, there were no substantial differences between the groups in the numbers of adverse events."
The time restricted group lost 27% more weight (although neither group lost more than about 1.5 pounds per month). The sample was laughably small. I still have lots of questions. How did the study define "obese"? More importantly (as regards the claims made by intermittent fasting proponents), how long had these patients been obese? What was their caloric intake prior to embarking on this study? What was their weight for the prior 12-18-24 months?
I wouldn't take a self reported study of 118 people to mean anything. The patients weren't provided with meals, they were merely "instructed" to eat a certain amount. There's no mention of prior BMI, activity levels, or frankly anything at all.
It's certainly not 'rigorous'.
8 to 4 is a pretty long window. I try and eat between 11 to 5. I know I eat less if stay in this shorter window. Basically 2 meals instead of 3.
I would agree that the dividing point is whether this causes you to actually eat less. For me, there is some benefit, as it usually eliminates my last snack of the night. Though I admit I have not measured it closely. Without that snack I might eat a bit more the next day without noticing.
What a relief! I threw in the towel on intermittent fasting after 2 hours.
"It seems to me you could still say that by shortening your time period for eating, you might eat less." Word. This seems perfectly clear: It is a technique to control your eating. The reason to do it is that if I eat all day, I eat a lot.
I used to lose weight quite easily but for the past six years, despite calorie and carb restrictions, I was stalled at losing weight and put it back on very quickly, which was never my pattern before. My doctor noticed that despite a fairly low-carb diet, my glucose and a1c levels were high normal, and I had a lot of diabetes in the family.
That's why she suspected insulin resistance, and suggested intermittent fasting. Actually, she suggested three things. 1) eat from 10-7 only 2) while I walk a lot, I don't get my pulse rate up so to do that at least 4 times a week for 15 minutes and 3) don't drink anything sweet, whether artificially or natural.
Those were in reverse order of difficulty. Most days I don't eat until 12:30 and try to end eating by 7:30. Easy. I hate raising my pulse, but I jog around the block and my pulse goes to 110, yay. Manageable. Giving up Splenda and diet drinks was brutal. But I did it. I finally added a bit of Stevia to coffee, not enough to make it sweet just to lose the bitter. I lost 20 pounds in 4 months and then stalled. Tried lower carb, smaller windows, nothing. No change. I lost the 20 regardless of method and stalled out regardless of calorie count or carbs or whatever. I'm eating around 1400 calories and walking 2 miles a day. I have an appointment with an endocrinologist because my doctor agrees it's weird, particularly since I also don't go into ketosis at all.
Long way of saying I thought that intermittent fasting was specifically for insulin resistance. Did they control for that in the study, or has the argument always been for all sorts of dieting and I missed it?
Hint: body fat is not equivalent to dietary fat. That said, distributed, moderate, proportional, nutritious meals matters.
I was 5'9", 275 pounds when I started intermittent fasting, eating at 10 and 4.....fewer carbs and got off diet coke....hunger the first three weeks but fine thereafter.....got down to 205, losing about 2 pounds a week.
Forgot to mention my intent was to improve my type 2 diabetes.
"Althouse, your "might eat less” triggered my STEM soul … That "might" epitomizes the unconscious observational bias that makes worthless many modern studies, much modern thought."
And even more, the reporting of said research. 'We can't tell the great unwashed masses the objective results of our study; there's no knowing what they'll do with it.'
Do people who repeat "calories/in calories/out" not realize that what and how you eat and exercise affect how many calories go in and how many calories go out?
You are not a wood furnace. Your metabolism is not static and is affected by lots of things, especially your diet.
Tina Trent said: "Years ago I found a weird cookbook by two previously obese research scientists who decided to eat almost nothing all day, then eat whatever they wanted for one hour. Fried chicken, potatoes and gravy, wine, chocolate cake. The rest of the day it was 200 calories total or less. They said the reward hour made the rest of the day bearable, and they showed dramatic before and after photos."
That sounds like Dr's Rachael and Richard Heller, who broke onto the low-carb scene with their book The Carbohydrate Addict's Diet. I read it back in the day and it's amazing how everything they advocated (and were mocked for) has proven to be true, or at least well-supported.
https://www.amazon.com/Carbohydrate-Addicts-Diet-Lifelong-Solution/dp/0451173392/ref=sr_1_1?crid=3VAYOL1Y1151I&keywords=the+carbohydrate+addicts+diet+book&qid=1650561800&sprefix=the+carbohy%2Caps%2C70&sr=8-1
The composition of the food you're eating absolutely matters. If you tell someone to eat a low-calorie diet with no further instructions, they're likely to eat a lot of processed carbs, which are technically less caloric than fats. (And yes, they might decide to eat mostly vegetables, but that wouldn't be most people's first choice.) But the only way to keep hunger at bay -- and your blood sugar levels steady -- on a time-restricted diet is by eating plenty of protein and healthy fats, and limiting carbs. In my case, I eat a wide variety of proteins and lower-carb produce, often with a healthy splash of extra-virgin olive oil for added flavor. I don't always stick to a limited eating window -- but when I do, I don't feel tired or hungry in between.
Even in China, where study apparently was done, this sort of data is particularly prone to...fudging.
I learned long ago that we are all our own science experiment. What works for you may not work for me.
I think there needs to be more variables controlled in this study -- what was the macro mix of the diets? Sounds like it was anything goes, but calories capped, no exercise element. I used to be a "calories are calories" guy but I know simple carbs/starches/sugars will push my weight up.
I'm a 16:8 intermittent faster most days, but I make sure I avoid sugars, try to keep my complex carbs higher. COVID-times lead me to stray. I ate a lot more comfort foods (think pizza and pasta) and snacked outside of my 8 hour food window. I added a COVID-era 10 pounds. As of 12/2021, I re-started my more focused IF routine and I'm back to "driver's license weight".
Your mileage may vary. Good luck staying fit and healthy, all. Find what works for you.
It is a demonstrable fact that mammal who are fed on a restricted diet that leads to the mammal being underweight and in a state of chronic hunger lead longer lives. There are some downsides to humans being in a state of chronic hunger. They beat their domestic partners and occasionally eat their children, but they are pretty much guaranteed to live longer... The plus side of intermittent fasting is that you don't have to live in a state of constant hunger to achieve these happy results. You just have to endure a few hunger pangs towards the end of day. These hunger pangs, rather than chronic hunger, are sufficient to lengthen the telomeres in your chromosomes and thus extend your life on average 22.7 years. Somewhat lower for non mask wearers but even those degenerates tack on an extra 14.8 years.....Well, anyway, speaking as an intermittent faster, it does help to assure bowel regularity.
There is a mathematical equation: calories in minus calories out. If that's a positive number, you gain weight. Any advice which might seem to complicate that is wrong.
That may be strictly true, but depending on how, what, and when you eat, other variables kick in. For many people, if a lot of the calories in are carbs, it leads to more hunger (like the old saw about Chinese food). I've found with IF and low-carb that I can eat pretty normal meals when I do eat (noon-8pm, but sometimes I skip lunch too), and I don't get ravenously hungry during the fasting time. I also found I could postpone hunger and meals with rigorous exercise, which kills two birds with one stone. I lost about 25 pounds over a couple of years, going from a BMI of about 26 to 22. My A1C went from 6.1 to 5.4, LDL down, HDL up. Maybe it was just that equation, but all I know is that it worked.
Intermittent fasting worked wonders for me. When I started the 8/16 approach in March 2017, I weighed 305. On Sept. 14, 2019, I weighed 223. The only thing I changed during that time was my eating window.
When I first started IF, and for a number of weeks after, during my window I tried to cram as much food down my throat to get me through the closed window portion. Over time, I got used to the new approach and crammed less and less food.
People like to claim that weight loss is simply a calculation of "calories in" minus "calories expended". Unfortunately, history shows that that is simply nonsense. The traditional weight loss approach is some form of restricted calorie intake diet yet most people that employ that approach fail. Why? Because of "adaptation". Your body will simply adapt to fewer calories in and start to expend fewer calories.
I found IF helped me overcome adaptation by confusing the adaptation mechanism. Since I crammed so much food in within my window, I don't think my body ever considered itself being starved and, therefore, did not reduce calorie expenditure to protect itself.
My Chinese spouse, who long doubted IF until she finally acknowledged that it was working for me, tried it to help her lose some weight (not that she actually needed to but, you know, women). After trying various approaches (the first few did not work for her), she finally found an IF approach that worked for her and I have to agree. At 48, she has the abs of a 20 year old. We are off to Italy in a couple weeks and she is quite excited to be able to fashionably be able to walk around Florence.
I lost 65 pounds, and I've kept it off for over 4 years. Smaller portions of the foods I like with nothing off limits. No depravation. Regular exercise everyday doing something I look forward to doing. Last meal of the day at least two hours before I go to bed, but that's about sleeping better, not about losing weight. No second helpings of anything until I wait at least 20 minutes. No calories to count. Nothing to weigh or measure. Just smaller size dinner plates and having a beautiful place to go walking and a four-legged companion.
After 1,300+ finger sticks over 4 months I've learned that the simple vs complex carbohydrate dogma is unfounded. I don't know if "calories are calories" (I tend to think not; the body can adjust it's own metabolism based on conditions), but a gram of carbs is a gram of carbs.
I've noticed the scientific community is coming around to this idea. The body has no more problem cleaving off a glucose molecule from a starch chain than it does splitting sucrose.
I think the study misses the point of why people do intermittent fasting. I find their results a big nothing burger, because they compared two groups who consumed the same amount of calories. Well, hell, I would expect similar results in that case. It is a trivial experiment.
The reason people intermittent fast is to reduce their total calories in the first place, and fasting helps reduce hunger pangs once you get used to it.
They should have compared a group who intermittent fasted versus a group who did nothing. That would mean much more.
Not the 8-4 time- it was fasting so many hours before breaking fast from your evening meal. Idk. I’ve never really dieted-
So, You're Tired of Being A Fat Bastard?
That’s it. I’m done.
I’m quitting my Slow Foods Society membership.
Watch out Chick-fil-A.
"sufficient to lengthen the telomeres in your chromosomes and thus extend your life on average 22.7 years. Somewhat lower for non mask wearers but even those degenerates tack on an extra 14.8 years."
Mmmm! Fudge!
“ Althouse, your "might eat less” triggered my STEM soul to depths which I doubt your artistic soul is capable of understanding. That "might" epitomizes the unconscious observational bias that makes worthless many modern studies, much modern thought. I won't bore us all with my ranting on the subject, but note well the violence of feeling it awakens.”
Ironically, you are expressing yourself in an emotive and uninformative way. Be explicit. I suspect you miss my point, which is that even though intermittent eating doesn’t help if the calories are the same, a person might be able to eat fewer calories by adopting a strategy of fasting for much of the day.
I'm a 12-6 window person myself.
To each his own, and I LOVE pasta, potatoes and bread, but intermittent fasting with low carb worked for me in one year, when years of following the typical weight loss advice of calories in/out, increased exercise and "six small meals a day" did not.
What finally worked (lost 80 pounds and easily maintaining) was eating one meal a day and less than 30 g of carbs.
Then just walk away from food.
Surprisingly freeing: no decisions every two hours about what and how much to eat. For a food person who is overweight, or an emotional eater, each eating decision represents two chances to fail (wrong food or too much) and say screw it. Six small meals a day is 12 hard choices.
Within 1-2 weeks, cravings, hunger and insulin spikes are over, inflammation is down, and your body will burn fat (at this point, yes, to make up the caloric deficit during the fasting window). Insulin makes you store excess sugar as fat, and it makes you hungry. Stored fat can only be burned when insulin is low and no new energy is coming in (such as during an 18 or 23-hour fast).
I followed the free eating framework at Eat Like a Bear website and FB group, interacting with many people with 100+ lbs. weight loss. Also see YouTube videos by Dr. Jason Fung, nephrologist from Canada, and his book The Obesity Code to explain how the 1970s food pyramid with carbs as the base (6-11 servings a day), along with super-sized portions and non-stop snacking, skyrocketed the nation's obesity and diabetes Type 2.
Well, I'm down 50lbs since last August eating One Meal A Day, preferably between noon to 3 pm. I don't really restrict calories, except I work to avoid sugars, especially fructose (I think I have an addiction). If I do have a snack late it is no more than cheese and salami. No carbs. My premise is to give my body a break from digestion to do maintenance and such. I have less reflux at night.
I think the addiction is that fructose triggers insulin then that triggers a mad desire for more sugar or at least something to eat, which causes me to eat more. I say fructose as I tried to manage sugar crashes last fall with glucose tablets but the didn't dull the cravings, but one sugar cube (50/50 glucose/fructose) did.
But this is a diet study so give it 6 months and the opposite will be reported.
3pm - 7pm window for me. I run 9 miles fasted every morning at 6am and walk 6 with the dog after dinner at 7:00pm. Eat very low carb, but not zero. When I eliminated all starchy veg and rice I found it very difficult to run worth a damn.
"I LOVE pasta, potatoes and bread, but …"
One very surprising result from running postprandial (after eating) blood glucose curves was potatoes and pasta within a meal doesn't cause a glucose spike for me. Eat them alone, however, and Katie bar the door.
The bottom line, said Dr. Ethan Weiss, a diet researcher at the University of California, San Francisco: “There is no benefit to eating in a narrow window.”
It's so science-y to make such definitive statements. Not "we didn't find an effect." But "there is no effect."
It boggles the mind that people give such deference to what passes for science. I would compare it to used car salewomen, but I don't want to offend the sales-people-with-naturally-formed-vaginas.
You do eat less, the way I've managed to keep my weight down throughout the years is to stop eating when I know eating more food would cause me to gain weight. I eat early and often and then I have to stop eating or I'll gain weight. I've not always been successful in doing that so my weight has fluctuated through the years.
All calories may be congruent, but they are nor equal. If you're a sloth, morning, day, or night, then reconsider consuming calories from carbohydrates that are quickly metabolized and stored as body fat.
offend the sales-people-with-naturally-formed-vaginas
Front, black... back holes presenting as vaginas in a model of sexual intercourse.
Thanks, Rigeldog. It was an interesting book.
Low carb is all that works for me. That, and running for political office. I was so nervous I almost puked up the little I did choke down. Lost 40 pounds in three months. I didn't even have time to exercise. I just spent morning, noon, and night asking strangers for money. It's a shitty diet but you might use it for a last resort. Fit in my high school jeans for the first time in 30 years.
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