Her original appearance in Transformers made her a pin-up, but since her debut role the A-list actress seemed to be getting skinnier by the day.
She was papped on the beach last year wearing a tiny black bikini which highlighted how bony she'd become.
Her controversial turn modelling lingerie for Armani also showed her stick thin back and arms, with visibly protruding ribs and a concave stomach.
Judging by the pictures taken on the set of her latest move This Is Forty, Megan's gained some weight and looks much better for it.Wearing a pair of leather shorts and a vest top, the 25-year-old actress had visibly more muscular thighs and curvier legs, arms and chest.
Megan's trainer Harley Pasternak said in response to the furore over the Armani ads: "People thought 'Oh she must be anorexic' but she's far from that!"
The trainer said Fox found it difficult to gain weight: "She gets frustrated at times because she's like 'I need to put on weight.' So she actually weight-trains to keep on that lean muscle tissue."