The Secret That Nearly Killed Her

Portia says she went on her first diet when she was 12 years old. She had started modeling and had to call an agency to tell them her measurements. She says when she told them her bust was 32 inches, her waist 27 inches and her hips 37 inches, the modeling booker paused and said, "Just tell people you're 34-24-35." Portia says that was the moment she decided she had to diet to be able to work, because her body wasn't good enough the way it was.

"After the diet, I'd do the job, I'd binge, and then I'd have a few days to get the weight off before I did the next job,” says Portia. “But as the jobs got booked back-to-back, I had to get the weight off faster, so I used laxatives, I used diuretics, and then when that didn't work, I was forced to purge...to throw up."

Portia says she wrote Unbearable Lightness for anyone who's ever struggled with her body image. Brutally honest and at times graphic, she says the book is written from the perspective of the sick person.

“I thought it was so important to be honest and to go so deeply...into the crazy part,” says Portia. “Even though I was kind of afraid to do it because I thought maybe everyone would think that I'm nuts. But I think it's really valuable because there is a point where a diet becomes a disorder."