The Biggest Loser, NBC’s hit weight-loss competition show, has a dark side beyond the feel-good stories of contestants changing their lives for the better, alleges a former contestant.

Kai Hibbard, who came in second place in season three of the reality program, referred to her time on the Biggest Loser ranch as a “fat-shaming disaster that I’m embarrassed to have participated in.”

Contestants were virtually imprisoned in their hotel rooms before leaving for the ranch, and unable to talk to friends or family once there. They were also immediately forced into a workout regimen that could last up to 6 hours a day. “My feet were bleeding through my shoes for the first three weeks,” Hibbard claims.

Hibbard’s health was severely affected by her participation in the show and remains so today. “My hair was falling out,” she said. “My period stopped. I was only sleeping three hours a night. My thyroid, which I never had problems with, is now crap.”

The physical toll from the show was only exacerbated by verbal abuse from the producers. “They would say things to contestants like, ‘You’re going die before your children grow up.’ ‘You’re going to die, just like your mother.’ ‘We’ve picked out your fat-person coffin’ — that was in a text message,” said Hibbard.

In addition, trainers enjoyed seeing contestants collapse mentally and physically. “They’d get a sick pleasure out of it,” said Hibbard. “They’d say, ‘It’s because you’re fat. Look at all the fat you have on you.’ And that was our fault, so this was our punishment.”

In a statement, NBC challenged Hibbard’s claims. “Our contestants are closely monitored and medically supervised. The consistent Biggest Loser health transformations of over 300 contestants through 16 seasons of the program speak for themselves.”