Who knew that a grueling work dictat could have such dramatic results?
The 29-year-old revealed the results of the strict diet she has been following, as she relaxed in Miami Friday.
Hathaway was ordered to control what she consumed by film bosses, who needed her to look under-nourished and pale.
The usually healthy looking Anne seemed self-conscious as showed off her waifish limbs and pixie haircut in a black two-piece as she enjoyed the cobalt blue waters.
She’s in the city for her friend Italian designer Valentino’s 80th birthday.
The Love and Other Drugs star is his beloved muse, and has her curves dressed by the legend at most of her big events.
The actress, who is engaged to actor and jewelry designer Adam Shulman, is believed to have lost around 16lbs in just three weeks before filming began in London last month.
She is said to have consumed around 500 calories a day – just a quarter of what is recommended.