The American Idol winner came out with the eating disorder in an interview with CosmoGirl. Clarkson said it developed in high school after she missed out on a role in a musical.
"I thought if I came back and I was cuter and thinner - then I'll get the role."
Kelly joins another past contestant, Katharine McPhee, as someone who has struggled with bulimia, during which you binge on a meal and then vomit it up afterwards. Clarkson's condition lasted for for six months until friends discovered her secret and begged her to get help.
"One of my guy friends caught on to it, and I just felt so ashamed and embarrassed. I literally went cold turkey and snapped out of it," Clarkson said.
Since beating the eating disorder, the singer vowed to be more positive about her body and promote healthy eating to her fans.
"I've got a butt, I'm Greek - I can't help that. And I think it's good for people to see normal. I love food far too much!"
Amen, Kelly. We love you just the way you are.