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
Charlize Theron in Monster
To play real-life serial killer Aileen Wuornos in 2003's Monster -- for which she won the Best Actress Academy Award -- Theron gained 30 pounds on her model-esque frame. "I’m very athletic looking...and I don’t know how I could have played that part with this body," she told Stumped magazine of why she didn't just use a fat suit. "I knew I had to transform my body to get myself into her physical skin."