Kelly Osbourne’s Dancing with the Stars upcoming appearance should not have happened. Why not? Because Kelly Osbourne and Dancing with the Stars have an interesting history of going back-and-forth for a couple of years regarding the Kelly Osbourne’s Dancing with the Stars participation.

Producers from Dancing with the Stars have asked Kelly Osbourne to join the show – only to get the same answer. “I’ve always said no,” says Osbourne. “But secretly I’ve wanted to say yes.” So what’s behind her decision to join this season’s cast? Kelly Osbourne’s weight loss aspiration, that’s what.

“I want to get fit,” she says. “Everybody that does the show has these amazing bodies.” After only two weeks of rehearsals in preparation for the show’s Sept. 21 premiere, Osbourne, 24, looks set to join their ranks. Kelly Osbourne’s weight loss is progressing nicely, and she claims that she has even gained some muscle mass.

Her partner, Louis van Amstel says, “I see her waist changing, from all the twisting. And her legs, she looks in the mirror and says, ‘Shoot, I’ve never had [that kind of toning]!” Along with practicing four hours a day, Osbourne attends Pilates class twice weekly, squeezing in workouts while on a book tour in the U.K. for her new memoir Fierce, which details how she turned to drugs and binge eating.

Osbourne “has never looked this healthy,” says Van Amstel. When it comes to diet, Osbourne swapped carrots for candy and cut back on carbonated drinks. “She’s really sticking to it,” Van Amstel says. “She wants this.” [via]