Can intermittent fasting help with weight loss and how can one go about it?
Ah Intermittent Fasting…one of the newest popular routes to weight loss.
Yes, intermittent fasting (IF) can help with weight loss.
But…
While most pedants will insist that you normally fast intermittently when you sleep, IF is usually defined as maintaining a longer fast than normal. The most commonly used IF strategy is a 16 hour fast with 8 hours of eating. Others include eating every other day or simply occasionally fasting for a day or even going as far as an 18–20 hour window or even One Meal A Day (OMAD).
Now, your body does change things up after fasting for a while. In some studies, HGH and Testosterone levels elevate after around 16 hours of fasting. Additionally Adrenaline may be released around this time elevating your metabolism after this time as well. Now, don’t get too excited, these boosts are not extreme or long lived. It’s thought that this happens to spurn you into action to go get food.
After 36–72 hours, though, your metabolism crashes as your body tries to maintain what energy stores it has for famine protection.
These hormonal changes aren’t actually the big deal about IF. I’m not sure they’re really significant enough to make a difference.
IF is just an eating pattern. You can actually gain weight on IF if you eat too much.
So what is it good for?
One thing about people is that we are terrible at controlling our eating. If we allow ourselves we’ll graze and eat more without being able to track it (because we’re also terrible at remembering how much we’ve eaten).
IF sets a hard boundary around when we can eat and if you can set that in your head, you’ll most likely eat much less.
I did IF for about 6 months, only eating between 12 and 8. I lost about 6% body fat (I’m at 14% now). Most of that was at the beginning, but I was able to maintain around 13.5% for most of the time.
Even with IF, how much you eat is very important
It’s just with IF you have better controls over this since you can only eat between particular hours of the day.
With even shorter eating windows you may also run into some other benefits since you’re getting all your food in such a short amount of time that you can’t eat too much and your body can’t digest the food enough to use it all.
I wouldn’t bank on the metabolic benefits, but you can definitely control your eating much better with IF allowing you to lose and control your weight better.
I wouldn’t bank on the metabolic benefits, but you can definitely control your eating much better with IF allowing you to lose and control your weight better.
UPDATE:
I’ve had a few submissions to this question that address how it “helps you get into a low insulin state.” While this is true…it’s kind of redundant when you address it in terms of fat loss since in order to burn fat you have to be in a low insulin state, generally.
I say generally, because when you eat, your insulin levels spike because your glucose levels increase, particularly with a meal heavy in simple glucose. In between meals your body will maintain strict controls over your glucose levels and it will continue to do so for 36–80 hours before you go into ketosis.
What this means is that by intermittent fasting you’re avoiding those spikes for as long as possible, keeping yourself in a fasted state for a longer amount of time giving your body more time to get rid of those fat stores…
But like I said, if you eat too much, you’re not going to burn off as much fat during your fasted time as you’re adding back to them during the eating time.
It’s like if you had a funnel that drains at 10 mL/s but you fill it up at 15 mL/s, it’s never going to completely empty. Even if you optimize the funnel and it starts draining at 14 mL/s it will still fill up.
IF helps…but it’s still not magic.
