Several sizes smaller than she was on American Idol, Carrie Underwood admits that being in the spotlight has changed her. "I gained weight on the show, but I didn't starve myself afterward," she has told Cosmopolitan. "I may think about it a little too much. I might feel guilty if I eat a pizza. But I've tried to be healthy and exercise as much as I can. If that's made me lose weight, I guess I needed to." To stay fit, the singer runs and kickboxes to stay in shape. And the vegetarian even rewards herself with stickers ("like a kindergartener," she joked to Oprah Winfrey in a 2009 appearance) for eating well. Take a page out of Underwood's book and treat yourself for doing the right thing for your body.