It may seem really great to be paid to gain weight, but these actors and actresses know that it isn't all fun and games. One actor even suffered a back injury that still plagues him to this day. Even so, celebs continue to undergo incredible body transformations to get into character. You'll barely recognize these seven actors and actresses!
1. Charlize Theron: Monster (2003)
Charlize Theron underwent a spectacular transformation to play prostitute and serial killer Aileen Wuornos, gaining more than 30 pounds. She says an interview with Stumped Magazine: "I don't know how I could have played that part with this body. I knew I had to transform my body to get myself into her physical skin." The performance won her an Academy Award for best actress.
2. Christian Bale: American Hustle (2013)
Christian Bale is known for his yo-yoing weight. After losing 63 pounds for 2004's The Machinist and bulking up to play Batman the very next year, Bale finally let it all hang out in American Hustle after gaining 43 pounds to play con man Irving Rosenfeld. "I ate lots of doughnuts, a whole lot of cheeseburgers, and whatever I could get my hands on. I literally ate anything that came my way," Bale told People magazine.
3. Russell Crowe: Body of Lies (2008)
After packing on 63 pounds, Crowe was nearly unrecognizable as the desk-riding CIA agent Ed Hoffman in Body of Lies. Crowe told Access Hollywood that gaining the weight wasn't all that difficult: "If you want to put on weight, you just elect to live a sedentary lifestyle. Just as soon as you stop actually being active and decide to eat whatever you want, then these two things will combine very quickly."
4. George Clooney: Syriana (2005)
In 2005, famously fit silver fox George Clooney gained 35 pounds to play CIA field agent Bob Barnes. Possibly due to his extreme weight gain, Clooney suffered a spinal injury performing a stunt that continues to bother him a decade later. While it doesn't make up for his injury, Clooney's performance earned him an Academy Award for best actor in a supporting role.
5. Renée Zellweger: Bridget Jones's Diary (2001)
Like most actresses, Renée Zellweger typically maintains a very thin figure, but in 2001 she threw that out the window, gaining about 30 pounds to play Bridget Jones, a single woman over 30 living in England who is struggling to get her health, career, and love life on track.
6. Jared Leto: Chapter 27 (2007)
Like other method actors before him, Jared Leto isn't afraid of extreme body transformations. For the 2007 drama Chapter 27, the slender actor gained a whopping 67 pounds to play Mark David Chapman, the man who killed John Lennon.
7. Matt Damon: The Informant (2009)
In 2009 Matt Damon gained 30 pounds to play the doughy businessman-turned-informant Mark Whitacre. "I just ate everything I could see," Damon revealed, including McDonald's meals, Doritos, and beer. "It was very, very easy to gain the weight. It was very, very fun, probably the funnest time I had working, because I didn't have to go to the gym after work."