Intermittent fasting - some questions

dydn11402

I've been looking into intermittent fasting and there is a lot conflicting information out there. Maybe someone here can help me out.

Is fasting just a way of achieving a calorie deficit or is it something else? Some say it is, and some say it is hormonal and teaches your body to use fat instead glucose for fuel after being in a fasted state (regardless of calories).

I doubt fasting alone would put me in a calorie deficit anymore than eating purposefully in a deficit. So is there a point in me fasting for weight loss without
counting calories?

Any insights are appreciated.

Retroguy2000

You'll lose the same amount of fat whether doing IF or not, with the same total deficit. It's just a tool that works for some people to better adhere to said deficit.

You'd think it's some magic bullet based on all the eulogizing it gets here, but no, it's all CICO in the end.

Hiawassee88

https://blog.myfitnesspal.com/what-to-know-before-you-try-intermittent-fasting/
https://blog.myfitnesspal.com/introducing-the-intermittent-fasting-tracker/
https://blog.myfitnesspal.com/6-intermittent-fasting-mistakes-to-avoid/
https://blog.myfitnesspal.com/popular-weight-loss-plans-ranked-by-rds/
https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2623528
https://pubmed.ncbi.nlm.nih.gov/24993615/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5064803/

All of these links are from MFP.

tomcustombuilder

Your weekly calories will determine if you gain mass lose mass or maintain mass. Many people like I F because it allows them to have a couple larger meals rather than three or more smaller meals that for a lot of people will not be satiating.

AnnPT77

The key question is: What's your goal?

If it's weight loss, focus on calories. Use IF if it makes controlling calorie intake easier for you, and don't use it if it makes controlling calorie intake harder.

If it's exercise performance, some of fasted performance is individual or subjective. For that, experiment.

Fueling is more complicated than "teaches your body to use fat instead glucose for fuel after being in a fasted state". Stated at that cartoon level of generality, it's pretty much nonsense IMO.

Most people's fasted state is not fasted enough to fully deplete glycogen, and we maybe wouldn't want it to be. (Fully depleted glycogen stores aren't necessarily a great thing, experientially.) Fuel sources in the moment depend on various factors, including the intensity of the movement being performed. There are also subjective factors, such as that some people underperform (energy level) when fasted, don't enjoy the unpleasant on-ramp to a long enough test to see if they'd adapt (I'm one).

Here again, if the key goal is weight loss, why care what the fuel source is in the moment? If you're in a calorie deficit on average over a day or few, the body's going to make up that deficit from stored energy sooner or later, and stored body fat is the preferred source for that. (Yeah, get way too big a deficit, you increase risk of burning muscle or other tissue you'd prefer to keep, because there are limits on how much fat one can metabolize from storage.)

Endurance athletes need to care about fuel sources in the moment, because they do have a risk of depleting glycogen to literally punitively-low levels. That's why they often use pure-sugars supplements during very long workouts. A few health conditions may make it matter what the fuel source is in the moment, too, but it's irrelevant for most of us. Our healthy bodies know what they're doing, best let them do it.

There are other health claims for IF, and I won't try to either sell them or debunk them. I don't personally IF - it would be unpleasant to me as a hedonist - and I've not needed to do so for any reason in order to lose weight, maintain a healthy weight afterward, get good exercise performance in the sports I favor, etc. YMMV. Others will make different choices than I do, and any of us may do so for good reasons or bad ones.

Best wishes!

dydn11402

So the science that says it's about the fasting adjusting your body's hormones so that you burn fat in a fasted state, is a bunch of baloney?

In other words, according to them, say I'm eating 1500 calories and not losing weight, but start intermittent fasting, eating the same 1500 calories during my 8 hour eating window, I will now lose.

I'd be curious to hear from people who have tried both ways of eating with the same amount of calories to see if the results were the same.

dydn11402

Thank you for thos links. The studies were interesting. Problem is I find that for every study that has results one way, there is another with opposite results.
I guess I can try for myself and see what happens...

Hiawassee88

https://www.ahajournals.org/doi/full/10.1161/JAHA.122.026484#d2071692e1
This is new 2023 information.
"Researchers found no association between restricting eating times and weight loss, said principal investigator of the study Dr. Wendy Bennett, an associate professor of medicine in the division of general internal medicine at Johns Hopkins School of Medicine. That included how long people ate after waking up, how long their window of eating was throughout the day and how close to going to bed they ate."

Years ago, I used to practice TRE, Time Restricted Eating. "I'd be curious to hear from people who have tried both ways of eating with the same amount of calories to see if the results were the same."

TRE is not the same as IF. TRE shifts the focus to how many hours per day you eat vs. how long you have to fast. Intermittent. If you're eating every single day, that's not really intermittent fasting. Intermittent means irregular intervals. Eating every day is TRE.

The app is here, but I think it's behind the curve. It was a thing and now it's not. My anecdotal evidence doesn't mean anything, so I've moved on.

tomcustombuilder

dydn11402 wrote: »

So the science that says it's about the fasting adjusting your body's hormones so that you burn fat in a fasted state, is a bunch of baloney?

yep pretty much. It’s like fasted cardio. You MAY temporarily tap into stored fat however once you eat again you’re replenishing calories. So to repeat once again, it’s overall weekly calorie intake that matters and not meal timing.

Fat loss is a product of a consistent weekly calorie deficit over time

Retroguy2000

dydn11402 wrote: »

So the science that says it's about the fasting adjusting your body's hormones so that you burn fat in a fasted state, is a bunch of baloney?

In other words, according to them, say I'm eating 1500 calories and not losing weight, but start intermittent fasting, eating the same 1500 calories during my 8 hour eating window, I will now lose.

I'd be curious to hear from people who have tried both ways of eating with the same amount of calories to see if the results were the same.

According to whom? Do they have a side gig selling bridges?

Hiawassee88

I think the best diet is the one that improves your health. If you can't maintain the weight loss, it doesn't matter how you went about it. None of it was worth two hoots.

Stop dieting. Eat the food you like. Track your data points. Don't compare your foods or weight loss pace to anyone else's. Don't compete. Don't commiserate all of your past dieting failures. Don't get stuck.

That means that running with the pack, following the herd and grazing with the sheep may hold you back. Break away and make this all about yourself. Find your own pathway to weight stability. Rebounding back and forth and UP and down for years or decades will no longer serve anyone. Be done with it. Make a stand with all of your heart and will.

No more dieting. I believe that dieting is the cause of eating problems and not the cure. No more food rules for me. Ever.

sollyn23l2

dydn11402 wrote: »

So the science that says it's about the fasting adjusting your body's hormones so that you burn fat in a fasted state, is a bunch of baloney?

In other words, according to them, say I'm eating 1500 calories and not losing weight, but start intermittent fasting, eating the same 1500 calories during my 8 hour eating window, I will now lose.

I'd be curious to hear from people who have tried both ways of eating with the same amount of calories to see if the results were the same.

Assuming you eat the same 1500 calories, yes, your body will do the exact same thing whether you eat those 1500 calories in 1 hour or over 16 hours. And, if your body needs more than those 1500 calories.... guess what it'll do.... burn fat to make up the difference. Doesn't matter if you eat 1, 2, 3, 4, or 5 times per day. The Rock knows. It doesn't matter. And yes, I've done both. And no, my body didn't care. At all.

cryonic_273

IMHO the main benefit of Intermittent fasting is its effect on your habits.
It forces you to adopt new eating habits and restricts the amount of time you think about snacking.
Its hard to do that but once the new behaviors become a habit - it reduces the amount of snacking.
That habit alone makes sticking to diet plans easier.

neanderthin

Yeah, IF isn't something your going to be able to chart progression and come to a conclusion on over a short timeline, so most draw the conclusion it's useless. As it relates to weight loss, calories are what matter and using IF for weight loss might help with excess consumption and snacking and change some satiety signaling in some people which could turn out to be beneficial.

joandumas42

Three years ago, I started TRE. I ate 3 meals a day, starting with breakfast at 10 am, lunch around 1 pm and supper at 5 or 5:30. Then no evening snacking which was my downfall. I lost 16 pounds over the next year, but didn't change the foods I ate. So I wasn't tracking calories, but obviously I was eating less due to not snacking at all. It worked well as I don't get hungry in the morning and I just drank black coffee. I always was on the lower carb side and didn't eat starches at dinner. Then I decided that if lower carb worked, keto would be better. So with the high fat and not counting, I gained it all back with some friends.

So long story short, I started counting calories on MFP and going back to higher carbs. Still put off breakfast until 9 or 10 am, and no snacks at all. Since January 23 Ive taken off 4 lbs. I'm very happy with eating oatmeal and berries and yogurt for breakfast, and a sandwich and milk and fruit for lunch. Dinner the same with protein and veggies and salad and fruit. That's my preferred way to eat.