Beyonce's Water Diet

I heard that Beyonce slimmed down for the movie Dream Girls by only drinking water with cayenne pepper. If this actually is true, Im sure it was a temporary sacrifice she made for the sake of her character. Seems like anytime she does something, whether is be movies or her music, she does it BIG. She appears to be a very hard worker and I commend and respect her for that. Personally, I don't think I would have the willpower to stick to only drinking water. I would go crazy.