Intermittent fasting and calorie deficits

Morning :)

I’m starting a bit of a new regime, and having heard a lot of people talk about intermittent fasting I thought I’d give it a go. I’m doing 16:8, and only eating between 2pm and 10pm, but I’m also logging what I eat and maintaining a calorie deficit.

Does intermittent fasting increase your metabolism so that your bmr is higher? Or is it just another way of limiting calorie intake?

If it is just limiting calorie intake that’s fine, it’s another tool in the box. But I find it interesting as I like to calculate my BMR to get my deficits right :) (I have a spreadsheet :p )


  • callsitlikeiseeit
    callsitlikeiseeit Posts: 8,633 Member
    its just another way to create a calorie deficit. nothing more nothing less. i could cram a WHOLE lot of food into 8 hours. though not intentional, I pretty much eat during an 8 hour timespan, just because of my daily schedule.
  • bubus05
    bubus05 Posts: 121 Member
    edited January 2021
    I think that the eight hour window is slightly to long for IF, I would decrease it to six TBH. In theory-many will disagree-it should extend the time period when your body is on low insulin level thus help it to burn fat more effectively. You are right it does help to control daily calorie intake.
  • ahclay
    ahclay Posts: 36 Member
    I've been doing the eight hour window for over three months, and it's working for me, but I also count calories and stay low-ish carb. The important thing is to fast for at least 2-3 hours before going to sleep, at least for me, because I sleep better on an empty stomach. Yes, it is another variation of calorie restriction, but it's working for me, and it's more manageable for me. I feel like I can do the window for life, whereas, if I ate all day and tried just to calorie restrict, I know that doesn't last!
  • ahclay
    ahclay Posts: 36 Member
    You have to put your own spin on any method, I think. I have done the six hour window on days when my schedule allowed, and it does work better, but at this point I'm not ready to do that full time. Also cutting flour and sugar works better for me than anything else. Overeating during your window defeats the purpose. Eat enough for your nutritional needs,but still keep it to 1-2 meals a day.
  • lgfrie
    lgfrie Posts: 1,447 Member
    It's just another way to create a calorie deficit. A fine way to do it, imho. I've been doing 17:7 for over a year and a half and I see no reason I'd ever stop doing it. Even when I took a 3 month maintenance break this summer, I (mostly) stuck with IF, except for 2 weeks (not coincidentally the period in which I regained a few pounds).

    When I started IF I was VERY hungry at night, but that passed in about 3 weeks and then I started having no appetite or interest in food outside the eating window. That has remained true ever since. This is my favorite feature of IF. So many of us are trained to respond to hunger pangs with food, like some evil Pavlovian experiment, but one thing you learn with IF is, another thing you can do with hunger pangs is just ignore them. And then, guess what, they stop. And then you're free!! I've gotten used to not being hungry and not obsessing about food but for the first 6 months or so of IF I found that remarkable.

    IF has definitely been a game changer for me. But there's really no question that if you eat 100 calories every hour of the day or 2400 calories for dinner, it's gonna have the same impact on your weight.