Anne Hathaway is reportedly on a 500 calorie diet.

The 29-year-old actress has apparently had to slash her daily food intake in a bid to drop two dress sizes in time for her death scenes in the movie adaptation of "Les Miserables."

The "Devil Wears Prada" star -- who plays single mother and prostitute Fantine -- is said to be surviving on just two apples a day and a protein shake.

A source said: "Anne is playing a destitute factory worker-come-lady of the night.

"Unfortunately, she only has 15 to 20 days to lose as much weight as possible -- up to a stone-and-a-half (21lbs) -- because she's been filming the scenes showing her fit and healthy, almost slightly chubby.

"It's not ideal but, as with any high-budget movie, there are strict time constraints."

However, the insider insists producers of the movie -- which also stars Hugh Jackman and Russell Crowe -- will be keeping a close eye on Anne's health.

The source told the Daily Mirror: "Anne knows the risk of such an extreme diet and will undergo weekly medicals to make sure everything is still functioning as it should do."