Intermittent Fasting Experiment

So you are going to eat the exact same 30 day meal plan as last month or are you going to repeat this meal plan next month without the IF?

Weight loss with intermittent fasting comes from maintaining a calorie deficit. That said, intermittent fasting, by its nature of removing meals, makes it easier to eat fewer calories. Easier, not guaranteed. It's astonishingly easy to gain weight on intermittent fasting if you binge eat, drink a lot of calories during your eating window, or fill up on garbage food.

As someone who has lost weight with both IF and OMAD, I would offer the advice of tracking your food and nutrition especially in the beginning to make sure you're eating fewer calories and that you are still getting the nutrients that you need for the day.

Also, drink a lot of water during your fasting time to decrease hunger, and make sure you fill up on nutritious but dense calories like lean protein and fibre during your eating window to avoid binging or reaching for high sugar high fat foods.

Good luck I know you can do it!

lgfrie wrote: »

Not sure there's really "mixed opinions" on IF. For some it's a great way to structure the eating day; for others, it doesn't suit them. I've been happily doing IF almost every day for half a year, but I've seen a lot of other people flop and flail with it during that time.

There's a bit of background noise from fans and detractors now that IF has achieved Fad status. Some people enjoy getting on board with new fads; others despise fads precisely because they are fads. But that's just background noise, neither the fault of IF as a way of eating, nor to its credit, especially since fasting existed for thousands of years before it was promoted to Fad status recently. Most sensible people would acknowledge that IF substantially helps some people with calorie discipline and therefore weight loss, but doesn't work for everyone.

As to running an experiment to see if it'll speed up your weight loss while holding calories and exercise constant -- it won't. Sorry. IF does not produce more weight loss per calorie not consumed; what it does do is help some people control their calories so that the weight loss can take place. That said, there's absolutely nothing wrong with trying it for a month, and you may well find that you like it and want to keep going with it.

Agree. However, my impression was that OP is not logging and won't be, but is just going to see if IFing without more will lead to weight loss.

If so, it might. Some people might naturally eat less.

For me, if I pushed my first meal to 2 pm and then ate at 8, as well as whatever I wanted in-between, and wasn't already being mindful about my eating or limiting portions or focusing on healthful eating or lower calorie dense foods, I could extremely easily gain weight eating that way.

But if I were mindful about my eating, ate generally healthfully and mostly home cooked stuff, and ate only at 2 and 8, I'd likely lose or (if a good weight already) maintain. But the same is true for eating three meals a day, no snacks, same mindful approach, and no logging.

An interesting experiment might be to see which of those two approaches felt easier with a set calorie goal or, if one preferred, if total calories consumed differed in the absence of logging (I don't think mine would much, as I understand it you think yours would, and we are both probably right).

A better trial if the OP wants to see if IF alone matters, calories the same, would be to use meals that cannot differ (packaged stuff and repeat the menu), and eat exactly the same for 30 days without and then with IF (and avoid varying activity). Hard to make sure it's really controlled. (It's still not a legitimate "experiment," but might be interesting as an N=1 thing.)

lgfrie wrote: »

lemurcat2 wrote: »

lgfrie wrote: »

Not sure there's really "mixed opinions" on IF. For some it's a great way to structure the eating day; for others, it doesn't suit them. I've been happily doing IF almost every day for half a year, but I've seen a lot of other people flop and flail with it during that time.

There's a bit of background noise from fans and detractors now that IF has achieved Fad status. Some people enjoy getting on board with new fads; others despise fads precisely because they are fads. But that's just background noise, neither the fault of IF as a way of eating, nor to its credit, especially since fasting existed for thousands of years before it was promoted to Fad status recently. Most sensible people would acknowledge that IF substantially helps some people with calorie discipline and therefore weight loss, but doesn't work for everyone.

As to running an experiment to see if it'll speed up your weight loss while holding calories and exercise constant -- it won't. Sorry. IF does not produce more weight loss per calorie not consumed; what it does do is help some people control their calories so that the weight loss can take place. That said, there's absolutely nothing wrong with trying it for a month, and you may well find that you like it and want to keep going with it.

Agree. However, my impression was that OP is not logging and won't be, but is just going to see if IFing without more will lead to weight loss.

If so, it might. Some people might naturally eat less.

For me, if I pushed my first meal to 2 pm and then ate at 8, as well as whatever I wanted in-between, and wasn't already being mindful about my eating or limiting portions or focusing on healthful eating or lower calorie dense foods, I could extremely easily gain weight eating that way.

But if I were mindful about my eating, ate generally healthfully and mostly home cooked stuff, and ate only at 2 and 8, I'd likely lose or (if a good weight already) maintain. But the same is true for eating three meals a day, no snacks, same mindful approach, and no logging.

An interesting experiment might be to see which of those two approaches felt easier with a set calorie goal or, if one preferred, if total calories consumed differed in the absence of logging (I don't think mine would much, as I understand it you think yours would, and we are both probably right).

A better trial if the OP wants to see if IF alone matters, calories the same, would be to use meals that cannot differ (packaged stuff and repeat the menu), and eat exactly the same for 30 days without and then with IF (and avoid varying activity). Hard to make sure it's really controlled. (It's still not a legitimate "experiment," but might be interesting as an N=1 thing.)

I've actually run something of that experiment, although I'm pretty sure a professional experimenter person (whatever they'd be called) could poke a thousand holes in it. I did diet for a couple months with very strict calorie logging before going to IF, and continued with the same logging and calories under IF. Also, I ate (and continue to eat) about 80 % of my meals packaged, from a healthy meal delivery service - they come with full nutrition labels. And I'm a pattern eater - I keep eating the same things over and over long after most other people would be crying out for variety LOL So, at least on an n=1 basis, I have half-way decent data.

I did find that I lost weight a bit faster with an IF approach, to the tune of 2.25 lbs/week versus 2.0, using MFP's calorie suggestion for 2.0 lbs. Pretty consistently too!! Stumped, I asked around as to what could possibly be causing that, because it didn't make intuitive sense that you could lose weight faster just by rearranging your eating schedule. Someone here on MFP pointed out that it could be that my TDEE increased as a result of being more active (or maybe just fidgety) from the fasting. And I decided that was probably the answer - I am a bit more energetic and less food-logged on a 16:8 diet than on 3 meals a day. For the same reason that people take naps or need time to digest food after a meal - food makes you a little sluggish. On IF, my post-meal sluggish periods were reduced to two, so maybe I was a bit more active overall, in subtle ways that wouldn't show up in intentional exercise calories. Maybe just going from a regular schedule to IF bumped me up from Sedentary to Lightly Active or half way to Lightly Active, so to speak.

So in my case, it's possible my TDEE is a lil higher with IF, although I did afterward adjust my calories upward because I don't seek to lose more than 2 lbs / week.

I think it isn't impossible that someone would see some incremental more weight loss under IF, because IF might increase one's TDEE a little. But I doubt that would work with everyone. And it definitely wasn't a huge amount - for me, a quarter pound a week, that is hardly a reason to adopt one WOE over another.

Yeah, one reason why the n=1 approach isn't the equivalent of a real study is that there are so many variables and it's also possible that people will lose more or less weight for a period for all kinds of reasons. I've also seen studies that suggest slightly better results eating farther from when one sleeps (so in some ways the opposite of the common "skip breakfast" IF pattern. I suspect any such effect would be outweighed by an eating pattern one did not find comfortable so I tend to dismiss them, but in an n=1 experiment I could see a possible effect from something like that too.

On a different note, I also often see people comparing "not IF" (by which they mean eating whenever they feel like it within their goal, no schedule) to eating 2 meals and a small snack (or something like that) within a window. I think a better comparison there would be 2 schedules where the only difference is the window concept -- 3 meals a day spread over 12 hours vs. 2 meals and a snack over 6, say.

I also see people who decided to lose and so went from mindless eating without calorie counting to doing IF (and also being mindful, eating more healthfully, trying to make more filling, lower cal choices, etc.) and just overall being motivated to lose in the latter case, and then saying that one cannot gain doing IF, as if IF were responsible for all the other things.

When I started I was super motivated, ate 1200 with ease (or 1200 plus exercise as I was exercising more), was working on gaining fitness, was home cooking most foods and not eating between meals, and lost super easily. Yet I don't think that was because of the window I was eating in (6 to 9:30, so about 15:30 hours) or the 3 meal pattern I prefer. (It would also be easy to claim this was due to eating more meat or eating largely un or minimally processed or all kinds of other things, but it wasn't that, it was that I was very motivated and so doing a variety of things that helped.)

Anyway, I am sure that some do feel more energetic eating some ways vs others or find calories easier to resist some ways rather than others, so it would not shock me for an n=1 experiment to find differences. I would be surprised if everyone had that same experience, as I do think it's overall calories and unlikely there's a big difference in TDEE on average based on eating window.