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Ways Fasting Can Help You Lose Weight, Say Dietitians

Exactly how skipping a couple meals a day can further your weight loss goals.

There are dozens, maybe hundreds, of ways to lose weight. There's the Mediterranean diet, a low-carb diet, the keto diet, the Paleo diet, Whole30, the list goes on. One of the increasingly popular weight-loss diets is intermittent fasting (IF), where you eat all your meals within a small eating window and fast for the remainder of the day. And that's it. You technically don't have to give up any of your favorite foods and you don't have to force yourself to eat any health foods that you dislike. So how can that be? How is it that you have free reign to eat whatever you want and all you have to do is limit when you eat it?

We talked to registered dietitians and looked at the science behind exactly how fasting helps you lose weight, and why it's a diet worth considering if you want to lose weight safely. So if you've been thinking about trying an intermittent fasting diet for weight loss, read on, and for more on how to eat healthy, don't miss 15 Underrated Weight Loss Tips That Actually Work.

It forces the body to switch into a fat-burning mode.

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When fasting, your body will more fequently burn fat stores for fuel than it would if you were eating throughout the day. "When you're fasting, your insulin levels and glycogen (muscle energy stores) go down [because you're not eating food]. As a result, your body switches from burning carbohydrates for fuel and taps into burning fat for fuel. This forces your body into ketosis (the goal of the keto diet)," say The Nutrition Twins, Lyssie Lakatos, RD, CDN, CFT, and Tammy Lakatos Shames, RD, CDN, CFT, authors of The Nutrition Twins' Veggie Cure and members of the Eat This, Not That! Medical Expert Board.

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It helps you regulate your appetite better.


"One of the biggest weight loss benefits of fasting and going into ketosis is the effect of ketosis on appetite. Since fasting reduces ghrelin (the hunger hormone), it can help weight loss hopefuls to feel more satiated and stay on track," say The Nutrition Twins, who reference this Nutrition Research study.

It helps maximize digestion hormone secretion.

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When you fast, you can sync your eating schedule with your body's circadian rhythm: the natural, internal process that regulates the sleep-wake cycle. By doing this, you can optimize your body's metabolism, helping it run more efficiently:

"When you synchronize intermittent fasting with your body's natural circadian rhythm, you eat during the day to take advantage of the way the body has evolved to maximize hormone secretion for digestion. By doing this, your body can more efficiently use food during the daytime to fuel activities," say The Nutrition Twins.

On top of weight loss, there's another health advantage to this method: it can help reduce your risk of diabetes. Part of the human circadian rhythm is to decrease insulin sensitivity throughout the day. Insulin is a hormone responsible for pulling glucose out of your bloodstream and into your cells. This means that when you eat a carb-rich meal at night, your body is exposed to more insulin, which can lead to an increased risk of type 2 diabetes over time. By fasting during this time, you can avoid this problem.

You won't eat late-night snacks that tend to be unhealthy.

man eating leftover pizza as a late night snack

"One of the best things about [intermittent fasting] is that you eliminate late-night snacking, which is associated with weight gain and that has also been shown to disrupt natural metabolic processes," say The Nutrition Twins.

Now before you go off and try fasting for weight loss, make sure you're not one of these 11 People Who Should Never Try Intermittent Fasting.

Olivia Tarantino
Olivia Tarantino is the Managing Editor of Eat This, Not That!, specializing in nutrition, health, and food product coverage. Read more about Olivia