Demi Lovato says school was much "harder" on her than the entertainment industry.

The singer-and-actress was bullied when she was younger, with things getting so bad she was eventually removed from mainstream education and taught at home.

In 2010 she went to rehab, and has spoken openly about her struggle with eating disorders and self-harm. Demi knows many think her problem stem from her career starting with Disney at a young age, but she insists that isn't the case.

"I'm 100% grateful for the roles I've been given, and I've had really supportive people around me. People say the entertainment industry is tough, but school was the hardest thing I've ever had to go through," the 19-year-old told Glamour magazine.

Talking about the bullying she went through is still difficult for the teenager. As she's learnt to deal with her issues she has come to realise none of it was her fault.

"I truly don't know why the bullies picked on me," she said. "I was teased about my weight, called names, called fat. I was just a normal kid. It was totally out of line."