Demi Lovato: Body Image Issues Began at Age 3, Opens up to Katie Couric About Bullying and Rehab

Demi Lovato opens up to Katie Couric about her struggles with bullying and body image on the upcoming episode of "Katie."

Lovato reveals on the Sept. 24 episode that her body anxiety began while she was still in diapers.

"I remember being 3 years old in a diaper and rubbing my hand over my stomach," Lovato recalls, according to E! Online. "I remember thinking in my head, 'I wonder if one day this will ever be flat?'"

The "X-Factor" judge's confidence sank even lower when at the age of 12 some of her schoolmates began calling her "fat." It was this formula for disaster that led to her battle with bulimia, cutting and depression.

"It played more of a toll on me than if I was physically abused in school," the 20-year-old singer said. "I've always said I wished that they had just hit me in the face and gotten it over with, because what they said to me sticks to me to this day."

In 2010, Lovato ended up punching one of her backup dancers in the facing causing a black eye and bruised cheekbone.

Lovato admitted to Couric that it was "huge mistake." "I wasn't really in control of my emotions at the time and I was just out of control and there's no excuse for it but it definitely showed everyone I needed to get help and I think two days later I was checking into rehab," the starlet said, according to GossipCop.

The singer is using all of her negative experience to create a positive future. According to E! Online, Lovato is the new ambassador for Secret deodorant's "Mean Stinks" anti-bullying campaign, which encourages girls to "gang up for good."