Transformers beauty Megan Fox lost so much weight during a period of depression, her hair started to fall out.
The star grew paranoid she was only successful as a result of her good looks, and deliberately piled on the pounds.
But her weight dropped dramatically when she became obsessed with her image while shooting scenes for upcoming movie Jennifer's Body.
Fox plays a high school cheerleader who turns into a man-eating killer when she is possessed by a demon in the film.
And she tried to convince herself she was losing weight in an effort to prepare for the role - but secretly knew it was because she felt so low.
Fox tells Britain's GQ magazine, "Really my only job is to look attractive. I was so angry about that, that I went in the opposite direction. I turned into a really butch bull dyke for, like, six months... Then I went in the other direction. From being a giant motorcycle-riding lesbian, I turned into a zombie. I lost, like, 30 pounds."
She adds, "I was like, 'I'm losing weight for the movie'. I was telling myself I was being method (method acting), which was so outrageous and ridiculous and not true.
"But I ended up getting sick and my hair started falling out and I was like, 'Oh f**k. I can't do this'... You lose too much weight, you're not getting your vitamins, you get sick. I was really skinny. I was depressed."