She wowed the judges on "American Idol" with her powerful voice, but behind her mega-watt smile was a painful secret - her addiction to food.
Mandisa is opening up about her battle with addiction and her lowest point in the fight.
"I went to my apartment, I didn't have to be back until the finale, and I ate and I ate and I ate and I watched nothing but television, and I was in the biggest slump of my life," Mandisa revealed.
She told "Extra" it was therapeutic for her to write about the struggle in her new book, "Idoleyes."
Now, after fighting back against the addiction, she has a new outlook.
"My goal is not to be a size two," Mandisa explained. "My goal is to be healthy."
Even Simon Cowell's comments about her weight on "American Idol" couldn't bring her down.
"I saw him the next time and told him I forgave him," Mandisa divulged. "He responded like a true gentleman."
Now Mandisa is revealing another secret - her crush on former "Idol" Ruben Studdard!
So - are they or aren't they?
"Ruben called me while I was on tour, I will say that," she said. "So we kind of played phone tag back and forth, and who knows?"
No doubt about it, that's a duet many would like to see!