Megan Fox gained weight to impress Michael Bay with her curves.

The 'Transformers: Revenge of the Fallen' star deliberately tried to fatten up before working on the comic book action movies because the 44-year-old director prefers women who are a healthy weight.

She said: "Mike doesn't like really skinny actresses. He's been traumatised by them for some reason in the past. So I always try to put on 8-10lbs before. I'm always the fattest I've ever been when making a 'Transformers' movie."

But the 22-year-old beauty - who is dating 'Beverly Hills, 90210' star Brian Austin Green - insists she has a carefree approach to dieting.

She added: "Anyway, my weight fluctuates constantly - I don't really take good care of myself. I just sort of exist and survive."

Megan is not the only Hollywood actress who has put on weight for a movie role.

Renee Zellweger went from a dress size six to a 14 in preparation for the 'Bridget Jones' films, while Oscar-winning actress Charlize Theron gained 28lbs for her role in 'Monster'.

(China Daily/Agencies May 11, 2009)