Anne Hathaway was determined to slim down for her role in new movie The Devil Wears Prada, and decided to use the Gallic technique for staying svelte by consulting hit book French Women Don't Get Fat.

The film is set in the world of high-fashion publishing in New York City, and the already shapely star was determined to lose pounds for her role--but only in the most stylish, pain-free way.

During the film she is derided for being a size six and drops down to an even tinier size four.

She explains, "I read French Women Don't Get Fat and followed all the advice.

"It's a great book. The thing I love about it is it's not a diet book--I just watch certain things."