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
Matt Damon in The Informant/Courage Under Fire
The married father of four has gained and lost weight for movies throughout his career. But he says it's more difficult to transform his body now that he's older. "I think I've become more of a glutton," he said after getting fit for Elysium. (He also lost weight for 1996's Courage Under Fire.) "When I did The Informant, I put on 40 pounds...That's the guy I'm most comfortable being."