Hayden Panettiere. (Nikki Nelson/WENN.COM)

Actress Hayden Panettiere has revealed she became preoccupied with her weight as a teen after her figure was criticized in a magazine.

The Heroes star was horrified when she saw an unflattering photo of herself in shorts with the word 'cellulite' printed next to her bottom, and the image sent her into a downward spiral, sparking body dysmorphia, a condition which affected the way she saw herself.

She tells Women's Health magazine, "I was mortified. It gave me such body dysmorphia for so long. But I remember reminding myself that beauty is an opinion, not a fact. And it has always made me feel better."

The former child star, now 23, has since managed to overcome her demons and she feels more confident than ever about her shape.

She says, "People can tell when you're happy with being you and when you're not. It's only cheesy because it's true. As I've gotten older and grown into my body, I've started realizing that the way you carry yourself and that light coming out of your eyes are the most attractive things about you."