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Why You Keep Hearing About Intermittent Fasting and What You Need to Know.

Why You Keep Hearing About Intermittent Fasting and What You Need to Know

I was watching a clip of Jimmy Kimmel saying something funny and I thought, “He looks like he’s lost weight.” I Googled it, because that’s the kind of person I am, and I learned all about how he eats 500 calories or fewer two days a week and then eats whatever he wants the other five days, including pizza and pasta and steaks.

Apparently there’s actually a fasting type diet based on this concept, but after I did more research I learned it’s not the only fasting diet out there; apparently different types of fasting plans are taking the diet world by storm.

Because of their popularity, I wanted to share the information I’ve gathered so far. First off the bat: pregnant women and anyone with a history of eating disorders shouldn’t try these diets, period, and those with a medical condition (like type 2 diabetes!) shouldn’t try any type of fasting without the express consent and oversight of their doctor.

What are fasting diets and how do they work?

So what types of fasting diets exist and what do they allegedly do? There’s the 5:2 diet that I mentioned above, which research indicates may be as good as a regular all the time calorie restriction diets at helping dieters lose weight. The same study showed that those who practiced intermittent fasting as opposed to constant calorie restriction (like on a regular diet) had greater improvements in fasting insulin and insulin resistance.

There’s also a “fasting mimicking diet,” (FMD) which was actually designed by longevity researchers and involves eating a pretty low number of calories over the course of five days; this is supposed to be done as often as once a month for people with certain health issues, or as little as once a year for people who are entirely healthy.

This protocol was tested on 71 people who completed one five day round of the FMD for three consecutive months. Those on the diet lost an average of 5.7 pounds, and saw a reduction in blood pressure and body fat. Dr. Longo, the head researcher, hopes to run a trial to find out if this protocol specifically helps people who have conditions like diabetes.

Lastly, there’s time-restricted eating. This simply means constraining your eating to a certain amount of hours per day. One popular book was written with the guideline to eat all of your food for the day within an 8-hour window and to fast the other 16 hours. Eating within a 10-hour window and fasting 14 hours is another popular choice. Dr. Longo, mentioned above, talks about eating all of your food (starting from when you first have coffee in the morning) over the course of an 11 or 12 hour window and fasting the rest of the time.

This type of eating may be the easiest, and there does seem to be some science that shows this is beneficial…at least to mice. One researcher found that mice, even those eating a high fat and or high fat/high sugar diet had better health outcomes and gained less weight when they consumed all of their calories in an 8, 9, or 12 hour window. Once their eating went beyond the 12-hour window, their health started to falter. In other words, it appears to be beneficial, at least to mice, to have a longer window of time for their bodies to rest and repair and not have to be digesting food. Human trials are sure to follow.

I’m gonna say it again: Don’t do anything without talking to your doctor. This is not something to fool around with, but if you get the go-ahead and are being monitored, choosing some sort of fasting regimen may have positive effects.

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.