Some stars go to great lengths to get into character. Matthew McConaughey, Anne Hathaway, Renee Zellweger, and Christian Bale are just a few of the many celebrities who've lost or gained significant amounts of weight for movies
Renee Zellweger in Bridget Jones's Diary
The usually petite actress packed on between 20 and 30 pounds to play the leading lady in 2001's Bridget Jones's Diary and its 2004 sequel, Bridget Jones's Diary: The Edge of Reason. "It's really just math," she said of gaining and losing weight for the movies. "I've been eating lots of really fattening food."