1. Matthew McConaughey
Matthew McConaughey dropped about 40 pounds for his Oscar-nominated role as Ron Woodroof in the 2013 movie Dallas Buyers Club. Diet coke, egg whites and chicken was the diet that got him there.
2. Christian Bale
Christian Bale shed serious pounds twice in his acting career so far : first for 2004’s The Machinist and then again in 2010 for his Oscar-winning role in The Fighter. For The Machinist, Bale lost over 60 pounds on a diet of cigarettes and black coffee to play the insomniac lead. He slimmed down for The Fighter mostly through excessive exercise.
3. Anne Hathaway
Anne Hathaway went all-in for her 2012 role as Fantine in Les Miserables. Not only was her head shaved, but she dropped about 10 pounds prior to production to play the single mother turned prostitute and then another 5 pounds during filming, largely on eliminating meat from her diet. It paid off, as Hathaway won the Best Supporting Actress Oscar for her performance.
4. Matthew Fox
“Lost” star Matthew Fox dropped over 40 pounds to play the villain in 2012’s Alex Cross. Unfortunately for Fox and the movie, his weight loss efforts were basically in vain, as the movie was a Box Office and critical disappointment.
5. Matt Damon
Damon lost over 40 pounds for one of his early roles, starring opposite Denzel Washington in the 1996 film Courage Under Fire. But his weight loss efforts had consequences – Damon nearly died because of it. The weight loss also altered his metabolism for several years.
6. Hilary Swank
Hilary Swank shed the pounds for Boys Don’t Cry, where she plays a girl who secretly wants to be a boy. It paid off, as she won the Best Actress Oscar for her role in the film.
7. Tom Hanks
Like Christian Bale, Tom Hanks also lost significant weight for two roles in his career. The first was in Philadelphia (20 pounds) and the second was in Castaway (55 pounds).
8. Jonah Hill
It wasn’t specifically for a role that Jonah Hill shed 40 pounds for after he appeared in 2011’s Oscar-nominated Moneyball, but an effort to get healthier overall. His weight loss was largely credited to eliminating beer from his diet and seeking the help of a nutritionist.
9. Natalie Portman
Portman lost 20 pounds for her Oscar-winning role in Black Swan.
10. Mila Kunis
Like her co-star Portman, Kunis also dropped 20 pounds for Black Swan.
11. Scarlet Johansson
Johansson had to slim down in order to fit into the Black Widow suit in Iron Man 2. She did it primarily through exercise and healthy eating.
12. 50 Cent
The rapper turned actor dropped 50 pounds for his role in Things Fall Apart, largely due to his liquid diet and hours of running on a treadmill per day.