weight cycle ilustration weight cycle ilustration A pattern of weight loss and subsequent gain can be harmful to your health. (Photo: Sangoiri / Shutterstock)

Why do we keep putting those pounds back on?

A new study helps explain why so many diets fail – and it's all in your gut.

We say enough is enough. We make a plan. We start counting calories, cutting out carbs, stepping up our workouts. We say no to crème brûlée and yes to kale. And slowly but surely, we start to see the pounds melt away. The exhilaration! The joy! The relief! The ... feeling that we've been here before, at this exact time last year, and the year before that.

It's called yo-yo dieting for a reason, and 45 million Americans fall victim to it every year. And though it seems easy to blame ourselves for this frustrating cycle, the reality is far different – and it may be explained by the bacteria in our own gut.

A new study out of the Weizmann Institute of Science in Israel, published recently in the journal Nature, found that changes in the microorganisms in the intestines may be responsible for the body's failure to keep weight off.

fish, nuts, olive oilNew findings show that stopping the cycle of yo-yo dieting is more complicated than just picking a better diet. (Photo: Tina Larsson/Shutterstock)

Those changes, which the researchers call "intestinal microbiome signatures," vary from person to person. And they might be a key factor in figuring out why people gain more weight than the previous cycle.

The researchers said the changes in the intestinal microbiome signature help reduce the levels of two beneficial compounds in the body: the flavonoids apigenin and naringenin. Furthermore, these changes interfere with UCP-1, a gene that affects how many calories we burn. It's those two factors, they said, that help speed up post-diet weight gain.

“Diets generally fail and don’t work, but not because they don’t work initially,” Eran Segal, a computational biologist at Weizmann and one of the study's lead authors, told the L.A. Times. “The problem is the weight regain.”

This finding also helps answer a larger, and more puzzling, question: Why do some foods affect people differently than others? Why can some people maintain their weight while chowing down on french fries and cheesecake, while others tip the scales at the slightest of cheat meals? This video from Segal and co-author Elan Elinov might help explain this phenomenon:


A potential solution, the authors said, is what they call post-biotic therapy, which would produce flavonoids in the gut to replenish those lost by dieting. Essentially, you'd be giving your gut a little boost to make up for the inevitable damage, and hopefully stopping the yo-yo cycle.


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Related Topics: Healthy eating, Science

Why do we keep putting those pounds back on?
A new study helps explain why so many diets fail – and it's all in your gut.