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Can this celeb-endorsed practice really shrink your stomach?

Did you see that selfie Kim Kardashian posted showing herself at the gym cinched inside a blue corset? It's not a fashion statement--Kim K. is a believer in waist training. See for yourself:

This newly trendy practice involves wearing a corset-like device for hours at a time to compress your core, which will supposedly decrease the size of your waist permanently over time. Kim's not the only star who's jumped on the waist training bandwagon, either. Earlier this year, sister Khloe Instagrammed a photo of herself wearing a similar garment. And Jessica Alba also revealed in an interview that she wore corsets for months after giving birth to her two daughters.

You don't have to be an M.D. to realize that "training" your waist to shrink sounds suspiciously iffy. In fact, experts generally agree that there's no way it can really work--and it might do real bodily harm. "Medically, it doesn't make sense that cinching your waist tightly will make it permanently smaller," said Dr. Mary Jane Minkin, clinical professor of ob-gyn at Yale School of Medicine. "Once you take the garment off, your body will return to its usual shape. It's also uncomfortable, restricts your movements, and if you wear it really tight, it can even make it difficult to breathe and theoretically could cause rib damage."

Believers say that the tightness of the garment makes you sweat a lot, but it's really not possible to perspire so much that you shave inches off her midsection in any permanent way. What does work to shed pounds around your belly? You guessed it--eating healthy and being active on a regular basis. It's not trendy, but it's the one thing that works, whether you want to drop baby weight or just a few stubborn lbs, Minkin said.