Mark Wahlberg gained 30lbs by consuming 7,000 calories a day for his role in "Father Stu," but quickly shed the weight and resumed working out.
Damon gained weight for his role in a movie, carrying most of it in his face. He had to slim down quickly after filming ended.
Million Dollar Baby
Hilary Swank's training for "Million Dollar Baby" included a daily consumption of 210 grams of protein for 90 days.
It's Always Sunny In Philadelphia
McElhenney gained 60lbs to play "Fat Mac" in It's Always Sunny In Philadelphia by eating Big Macs, Krispy Kreme donuts, wine, and melted ice cream.
Bridget Jones's Diary
Zellweger gained weight for her role in "Bridget Jones's Diary," which earned her an Oscar nomination.
Bale gained 43lbs for American Hustle by eating doughnuts, cheeseburgers, and anything he could find.
Cooper gained 40 pounds of muscle to play the deadliest sniper in history.
Leto gained 67lbs to play Mark David Chapman in a film by drinking microwaved ice-cream mixed with olive oil and soy sauce. The diet left him with health problems.
The Lovely Bones
Ryan Gosling gained 60lbs to play a grieving father in The Lovely Bones, and like Leto, he also drank melted ice-cream to help with the weight gain.
Williams gained weight to play her character in Blue Valentine. She ate ice cream for breakfast and dinner and avocado sandwiches all day to prepare for the role.