Anne Hathway has gone in for extreme dieting for her role as Fantine in "Les Miserables".

According to the Daily Mail, the actress, 29, has been ordered to lose 16lbs in less than three weeks to play dying prostitute Fantine in the movie adaptation of Victor Hugo's famous book. As fans of the musical classic will know, the single mother ends up with consumption and later appears as a ghost.

The star is currently in the right size, 10 to be precise, for the shooting of the scenes before the character falls ill. However, to shoot scenes post her sickness, the actress has been asked to reduce her calorie intake from 2000 to 500.

"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 - 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.Producers have assigned her a personal trainer and she is literally eating nothing more than a couple of apples a day, and some protein - mainly in the form of a shake. 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," a film source was quoted as saying by the Mirror.

According to the Huffington Post, this is not the first time the actress has gone dieting for her roles. Anne apparently lost weight for her role as Catwoman in "The Dark Knight Rises".

Eddie Redmayne, Hugh Jackman and Russell Crowe are the other stars in the movie that will hit the theatres by December 2012.