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VERIFY: Does intermittent fasting help you lose weight?

Ready to eat for eight hours and fast for 16? If you can tolerate it, the research is promising. But why does it work?

DALLAS — Have you heard about intermittent fasting?

It's a diet where you restrict eating to something like an eight-hour timeframe and fast for the other 16. Another method is called alternate-day fasting, where you only eat 500 calories today, but you can have anything you want tomorrow.

Celebrities like Jennifer Anniston, Hugh Jackman and Chris Pratt swear by it. Maybe someone you know does too.

Here’s what I want to know. Is there a link between intermittent fasting and weight loss?

For answers, I'm looking at published research and talking to Dr. Krista Varady who researches intermittent fasting at the University of Illinois-Chicago.

“Is there a link between intermittent fasting and weight loss?” I asked her.

“Yes, there is a link between intermittent fasting and weight loss,” Varady said.

So, it works. But how well does it work?

Varady co-authored this paper in the Journal of American Medicine/Internal Medicine. It looked at the weight loss associated with alternate-day fasting. Over a year, participants experienced a 6% weight loss.

A smaller study Varady also co-authored looked at eight-hour, time-restricted eating. It found participants lost 3% body weight over three months.

And this paper in the Annual Review of Nutrition analyzed 16 research papers on intermittent fasting and found "...almost any intermittent fasting regimen can result in some weight loss."

Online you can find articles that claim things like, “fasting boosts metabolism” or “7 Ways That Intermittent Fasting Boosts Your Metabolism to Burn Fat.”

Is that true?

“Does intermittent fasting actually help you burn more calories?” I asked Varady.

“Intermittent fasting does not help you burn more calories,” she said.

“Intermittent fasting helps people lose weight just because they end up eating less. It's not like revving up their metabolism. You're fooling the body into eating less in some way,” Varady said.

So is there a link between intermittent fasting and weight loss? Yes.

But the reason why is not a mystery — it’s common sense. Intermittent fasting helps you eat less food.

Got something you want verified?  Send me an email: david@verifytv.com. 

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