Nov. 3, 2010 -- Actress Portia de Rossi says her decades-long battle with eating disorders was an "excruciating" experience that drove her to starve herself and at times eat only 300 calories a day.
"That was my diet," de Rossi told Robin Roberts today on "Good Morning America.
"Ever since I was 12 years old, I would starve myself daily and then binge after the job was over. And that was just the diet I returned to every single time I needed to lose weight."
The star's struggle with anorexia and bulimia started when she was modeling at age 12.
"From that age I learned that what I looked like was more important than what I thought, what I did and who I was," de Rossi, 37, said. "I think when your self-esteem is based on how you look, you're always going to be insecure. There's always a fresher face, a thinner girl.
"I had to diet to be professional, to make sure that I kept working," she added.
De Rossi goes into the depths of her illness in her new book, "Unbearable Lightness: A Story of Loss and Gain."
The Australian actress, born Amanda Lee Rogers, rose to fame in 1998 when she joined the cast of the hit TV series "Ally McBeal."
Rolling Stone magazine touted her as "a hot bombshell" and the media were taken by her glamour and sex appeal. But on the inside, de Rossi said, she was miserable. A closeted lesbian, she was afraid of being outed by the press.
"It should have been the best time of my life," de Rossi said. "It's the kind of dream job that actresses pray they get. And yet I was terrified of being exposed as gay.
"That was really the hardest part; all of a sudden being some kind of celebrity and being on a hit TV show. Who I was was completely unacceptable, so I had to create a character of someone I thought that people could accept."
De Rossi was eventually outed by a member of the paparazzi, and she now says she's glad that happened.
"She forced me to come out to my family, she forced me to live a more honest and more open life," de Rossi said. "How can you be angry at someone who makes you more honest and ultimately a lot happier?"
Portia de Rossi on 'Excruciating' Eating Disorder Battle
While filming "Ally McBeal," "I was constantly looking for external validation," de Rossi told Oprah Winfrey in an interview Monday.
"One friend of mine said to me, 'You look like a normal, healthy woman, and those three words really sent me into shock. Normal? Who wants to be normal? Who wants to be normal weight range? 'Healthy' suggested that I was kind of, like, pudgy. 'Woman' suggested curvy. I wanted to be a skinny, straight up and down girl."
De Rossi hit rock bottom in early 2000 when her weight plummeted to 82 pounds. At that point, she was taking in only 300 calories a day and obsessively working out.
"It was excruciating. It was very hard," she said.
A year later, she reportedly collapsed on the set of the film "Who Is Cletis Tout?" and was taken to a doctor, who found she was suffering from cirrhosis, oesteoperosis and organ failure.
De Rossi married comedian and talk show host Ellen DeGeneres in 2008.
DeGeneres talked to Winfrey about the book as well: "She hated herself," DeGeneres said. "I mean, she absolutely hated herself. I don't know, I look at her and I just think, 'How did you ever – I mean, how did you not know how amazing you were?'
"It's heartbreaking. I knew that she had suffered with eating disorders, but nobody really sees the ugly, deep, dark places that she takes you in that book."
But de Rossi said her family knew how sick she was, and writes candidly in the book about a time when her brother confronted her about her illness.
"He saw me working out at the gym and he saw how emaciated I'd become," she said. "I'd never seen him cry before but he just broke down and said you're going to die. ... It kind of punctured that obsessive mind of the anorexic thinking and it made me try to get a little healthier. And, eventually, I really do credit him with turning things around for me."
Portia de Rossi on 'Being Comfortable in Your Own Skin'
Today, de Rossi says that when she looks in the mirror, she knows she's not perfect, but that's perfectly fine with her.
"The message in this book for me is all about self-acceptance and being comfortable in your own skin," she said. "I think that it's important to not be so concerned about how you look. As women, it's really important to be focused on things other than what is on the plate in front of you and get on with your life and develop your mind and career and not be so obsessed with how you look and what you weigh."
Click HERE to for Web-extra resources to combat eating disorders.
Books Portia Recommends:
"The Eating Disorder Sourcebook," by Carolyn Costin
"Your Dieting Daughter," by Carolyn Costin
"100 Questions and Answers About Eating Disorders," by Carolyn Costin