5 Matt Damon – “Courage Under Fire”
Matt Damon came into his own as a serious actor in 1997, thanks in part to the extreme physical changes he made to portray a veteran addicted to narcotics and plagued by his past in “Courage Under Fire.” Damon exercised extensively and lost over 40 pounds, shocking director Edward Zwick when he appeared on set for the first time. The actor’s emaciated state had many concerned for his health, but he remained committed. After shooting completed, he finally went to a doctor, who put him on medication to correct his blood sugar imbalances. Although the effects of his dramatic transformation lasted longer than he thought they would, serious directors started to pay attention to the young actor and his career took off.
4 Charlize Theron – “Monster”
Charlize Theron‘s portrayal of serial killer Aileen Wuornos in the 2003 film “Monster” came as a shock, given that most people associated her with glamour and beauty. Theron didn’t want to simply put on the character like a suit—this was a real person, who should be depicted as the person she was. To prepare for the role, she gained 30 pounds, and appears in the film with minimal makeup, blotchy skin, and stringy hair. Theron didn’t see any other way to get into the character than to live in her body—and considering she won an Oscar for her performance, she must’ve been right.
3 Rooney Mara – “The Girl With the Dragon Tattoo”
When Rooney Mara was cast as Lisbeth Salander in 2011’s “The Girl With the Dragon Tattoo,” she underwent a dramatic change in appearance. She had much of her hair shaved and the rest dyed black—but changing hair color and length is something actresses do all the time for different roles. Mara’s physical changes didn’t stop there, though. She got her eyebrows bleached to the point they were nearly invisible, and acquired several new piercings in her nose and ears. By the time the transformation was complete, Mara admitted she barely recognized herself in the mirror.
2 Robert De Niro – “Raging Bull”
To portray legendary boxer Jake La Motta in the 1980 film “Raging Bull,” Robert De Niro essentially set out to become him. Before filming began, De Niro began workouts modeled after those La Motta himself would have done as a fighter. But transforming himself into a lean, mean fighting machine was only half the story—for the latter part of the film, De Niro had to pile on the pounds to depict the bloating, washed-up older La Motta. During filming, the actor ate virtually everything in sight in a bid to gain weight—and gain weight he did, going from 140 to 215 pounds. Though praised for his brilliant and authentic performance of the boxing legend, De Niro had difficulty losing the weight he gained for the role and struggled with depression as a result.
1 Christian Bale – “The Machinist”
In preparation to play an insomniac in 2004’s “The Machinist,” Christian Bale went on a diet consisting of coffee, cigarettes and an apple a day. The 6 foot, 2 inch actor dropped nearly 70 pounds over several months—a third of his previous body weight. Of course, it stands to reason the character wouldn’t have had the physique Bale sported in “American Psycho,” but his emaciated frame was more than a little disturbing. Perhaps even more shocking, Bale beefed up in just six weeks after shooting wrapped, building himself back up to his previous weight so he could play the title character in “Batman Begins.”