“A waist trainer will help you get the figure you want and feel sexier and better about yourself,” Zolciak-Biermann, 37, said.
Zolciak-Biermann says she has been wearing her waist trainer for more than a year.
"I wear it four to six hours a day, every day, and that's it. Some people wear it to bed. I don't wear it to bed; I want to be comfortable," she said.
Zolciak-Biermann said her small waist and curves last even after she takes the waist trainer off.
“I didn't wear it for seven days while I was on my honeymoon and my body didn't go back,” she said.
Zolciak-Biermann’s experience isn’t typical, said Dr. Sharon Bergquist, a professor of medicine at Emory University School of Medicine in Atlanta.
“The results from these are really temporary, so when you take them off, you don't keep that Barbie dimension you have when you're wearing them,” she said.
More than a dozen doctors told “GMA” they’re not concerned about short term-term waist trainer use, but they said long-term use can cause side effects.
“It can pinch a nerve … And if the upper part kind of pushes into your ribs, that can affect your breathing,” Bergquist said.
Zolciak-Biermann wears the popular waist trainer brand, “No Waist Clique.” In a statement, the brand told “GMA” that all its customers “receive excellent permanent results.”
The statement added that their waist trainers reduced the waist by inches, tightened abdominal muscles, flattened the belly and provided back support and improved posture.
Bergquist takes issue with those claims, saying “that’s just not substantiated in any type of clinical study.”
“GMA” asked No Waist Clique officials whether they it had conducted any studies on their product, but we did not receive a response.
Zolciak-Biermann said she has not had any problems and she’s hooked.
“I love it,” she said. “I think it's worked for me, it's worked for a lot of people that I've given it to.”