Disney star's desperate dieting ordeal

Disney star Demi Lovato was once so desperate to lose weight she starved herself and vomited until she was spitting up nothing but blood.

The singer/actress stunned fans in November when she pulled out of her world tour with the Jonas Brothers and checked into rehab for unspecified "emotional and physical issues".

The 18-year-old has since spoken out about her life-long battle with anorexia and bulimia, revealing her disorder was so much more than extreme dieting and throwing up after meals.

"When I was about 15, I was only eating two meals a week, but I wasn't losing any more weight because my body adjusted to that," she told People magazine.

"So I tried new things: laxatives, fasts - nothing was working.

"I decided maybe I should start throwing up. At my worst, I was doing it five times a day. I threw up so hard and so much, it was just blood in the toilet."

Lovato felt her world crumbling around her and knew she had to face up to her body issues before it was too late.

She says, "My eating disorders have ruined my life. I thought I could control it, but I couldn't. I ended up in treatment at the most untimely moment in my life."

The actress insists she's bouncing back after completing an intense three-month program, but every day is a struggle: "It is more difficult now because I don't have people supervising me. That's why I haven't been working.

"My goal for every day is to eat three meals, and that's challenging enough. There are days when I feel so overwhelmed, like I can't do it... I'm still learning just to like food... I'm determined to fight this. I've never been more peaceful or happy in my life. What's important is to help others get to this place."

- AAP