Katharine McPhee says "Idol" saved her life

Simon Cowell called Katharine McPhee's voice "the best of the competition," and millions of fans agreed; viewers all over the country caught the "McPheever" and voted her all the way into the "American Idol" finale.

But McPhee says just before her successful run on the show, she was finally putting an end to her fight with bulimia.

"When I made it onto American Idol, I knew that food - my eating disorder - was the one thing really holding me back," McPhee said in a new interview with People magazine. "I was bingeing my whole life away for days at a time...So when I got on the show, I said, 'You know what? I can do well in this competition. Let me give myself a chance and just get a hold of this thing.'"

After flying through the first rounds of the competition, McPhee realized she would need to beat her disorder in order to compete at the peak of her ability. She joined a treatment program at Los Angeles' Eating Disorder Center of California and went through three months of individual and group therapy. In the end, McPhee lost 30 pounds and finally broke her bingeing and purging cycle.

"That's why I say 'American Idol' saved my life, because if I hadn't auditioned I don't think I would have gotten a handle on food," McPhee said.

The "Idol" runner-up releases her first single "My Destiny" Tuesday and is joining her fellow finalists on the American Idols Live! tour this summer.