How small can Kim Zolciak's waist get?!
The former Real Housewives of Atlanta star, who already shocked her fans in March with her alarmingly tiny waist, recently Instagrammed that she lost four inches off her waist due to the celebrity-endorsed waist-training trend.
PHOTOS: Celebs In Their Underwear
And in case you think the 37-year-old mother of six is Photoshopping her jaw-dropping pics, she also shot a video proving her results.
"Sooooo I made a video since most of you think I photoshop my pics! I don't cause I don't need to!" she wrote. "I have horrible posture (carrying the twins did me in) and it really helps that too at least for me. I recommend the waist trainer because it works so well for me and I like to share with you guys what products I love since there are so many out there!"
But even if waist training is endorsed by seemingly everyone from Kim and Khloe Kardashian, to Ciara, to Jessica Alba, wearing a super-tight corset also has some serious risks. According to Yahoo Health, wearing the constricting undergarment can result in acid reflux, bruising of your bones, oxygen shortage, cause problems with blood clots, and in more serious cases, even harm the spleen and cause trouble to kidneys.
And it might not even work.
"Wearing a corset won’t make you lose fat around your waist," Holly Phillips, MD, a New York City-based internist, tells Yahoo Health. "What is a myth is that you can change your bone structure by wearing them. For [adult] women, your bones are formed. You can bruise them and harm them, but you can't change them."
"The corset itself doesn't have any direct effect on your fat or anatomy," adds Andrew Miller, MD, a New York City-based plastic surgeon. "If you stopped wearing a corset, eventually you're just going to return to the way you were."
PHOTO: The Already Super-Slim Ciara Joins the Waist Training Trend
Check out eight celebrities who swear by waist training in the video below.