Character: Aileen Wuornos, a former prostitute turned serial killer
Weight change: Theron gained 30 pounds to play Wuornos.
Method: After getting sick of Krispy Kreme doughnuts, Theron said she was never found without a bag of potato chips.
There's more: According to Theron, Wuornos had written down her insecurities about her body. Theron said she chose real fat over prosthetics to achieve the same mind-set as Wuornos and better act the character.