She's fit and zen now, but when she was a teenage pop star Alanis Morissette was anything but.

As the Ottawa native confesses in the July 4 issue of Us Weekly, between the ages of 14 and 18 she battled low self-esteem that sparked a major struggle with anorexia and bulimia.

Morissette -- speaking to the magazine while promoting the 10th anniversary acoustic release of her breakthrough album Jagged Little Pill -- says her battle was prompted by "hardcore" pressure from those steering her career.

"I recall being called to a meeting at the recording studio, and the person said, 'I know I called you to redo vocals, but I actually wanted to talk to you about your weight. You can't be successful if you're fat,' " she remembers.

Morissette said at the time her weight jumped up and down between 15 and 20 pounds. She would barely eat for months at a time, subsisting on Melba toast, carrots and black coffee.

"Constantly dizzy," she recounts about once having nothing to eat one day while a person working on one of her videos put back a large pizza.

"He was like, 'You can't eat. And don't even put milk in (the coffee,)" the singer told US.

Morissette said a friend intervened after one particularly drastic weight loss, which is when she started therapy and learning about eating disorders.

"My brain had really been programmed, and it has been a long process to un-program it," she told the magazine. "I try to remember, whatever my body is, it's perfect the way it is."

Morissette said these days she veers between being "uber-health-conscious" and allowing herself treats, like a chocolate fondue. She said her fiance, Vancouver actor Ryan Reynolds, loves how balanced she is about food.

"I work out about two times a week instead of nine," she said. "I'm still a part of society, but I'm better able to challenge it than when I was 14."