Film star Anne Hathaway credits a strict diet of dried oatmeal paste for helping her shed about 11kg for her role in the forthcoming big screen musical Les Miserables.

"I had to be obsessive about it - the idea was to look near death," Hathaway said in an interview with Vogue about preparing for her role as the consumptive prostitute Fantine in the musical version of Victor Hugo's classic 19th-century French novel.

Hathaway, 30, is quoted in the December edition of the magazine as saying that she first lost 5kg to begin filming and later dropped another 7kg by restricting her eating to nothing other than two thin pieces of oatmeal paste a day.

"Looking back on the whole experience - and I don't judge it in any way - it was definitely a little nuts," said The Dark Knight Rises actress.

"It was definitely a break with reality, but I think that's who Fantine is anyway."