1 of 10
I FACED OVERWHELMING HUNGER
Adam Driver recently opened up to Interview magazine about losing an incredible amount of weight for his role in Martin Scorsese’s film Silence. "He asked us to," Driver said. While shedding the pounds was incredibly difficult, the Girls actor respected the process. "I can't control what's happening in scenes, but I could control when I ate food," he said. "And that visual part of the storytelling, I don’t think I've ever taken it to the extreme before. It's an interesting thing."
2 of 10
I ATE ONE MEAL A DAY
While preparing for his role in The Lost City of Z, Robert Pattinson ate as little as one meal a day. "I had literally eaten nothing for the entire time," he explained to PEOPLE of the diet he followed to embody a 1920s adventurer who disappears in the Brazilian jungle. "I loved it afterwards, for like a week in London, where I have a 28-inch waist. I was like, 'Ooh! Skinny jeans.' " Pattinson admitted that his transformation was very short-lived, however. ("That lasted for, like, three days.")
3 of 10
I STALKED A WOMAN
To tap into the serial killer mindset for The Fall, Jamie Dornan confessed to following a woman off of the train, which is a decidedly darker twist on our usual dreams about the Irish actor. "It felt kind of exciting, in a really sort of dirty way," he told the Los Angeles Times.
4 of 10
I WENT TO A SEX DUNGEON
Of course, Dornan has already proved he is nothing if not a disciplined thespian. Key word: disciplined. "For research on a rainy Tuesday evening, I kissed the wife and baby goodnight and went to watch a dominant-submissive session in a dungeon," he said of getting red room-ready for Fifty Shades of Grey.
5 of 10
I LIVED IN A HOMELESS SHELTER
"I love pushing boundaries and challenging myself," said Vanessa Hudgens, who stayed true to those words when she headed to New Jersey's Several Sources Shelter. "I pushed myself so hard and so far, and as soon as we were finished filming, I had no clue who Vanessa was," she told PEOPLE after playing a homeless teen in the 2013 drama Gimme Shelter.
6 of 10
I DANCED AT A STRIP CLUB
No, no – this wasn't part of Kristen Stewart's prep for those honeymoon Twilight scenes. Instead, she learned how to work the pole at a run-down New Orleans strip joint for the 2010 indie flick Welcome to the Rileys. "I danced on the bar there three nights this week," she told Entertainment Weekly at the time, "and my legs are covered in bruises."
7 of 10
I LIVED OFF OF DRIED OATMEAL PASTE TO LOSE WEIGHT
Anne Hathaway is among the legacy of actors who've dramatically changed their bodies (and what's on their plates) for a movie. "I had to be obsessive about it," she said of prepping for her Academy Award-winning role in Les Misérables. After a strict cleanse resulted in a 10-lb. weight loss, she ate two thin squares of dried oatmeal paste a day for two weeks to shed 15 more pounds.
8 of 10
I STOPPED GOING TO THE GYM
Okay, this one sounds like a piece of cake … unless your name is Jennifer Aniston and you were put on this great planet to inspire us mere mortals. "At first I was thrilled because I said, 'This will be so great. I don't have to work out,'" said the Cake actress, who made her dramatic turn on the big screen playing a car-crash survivor suffering from chronic pain. "After a few weeks, it really does start to affect your sleep, your stamina throughout the day, your mood."
9 of 10
I DROPPED 40 POUNDS – FAST
In order to get into character for his role as "Deaf" Smith (who had consumption) in the upcoming History Channel miniseries Texas Rising, Jeffrey Dean Morgan ate just one can of tuna a day, dropping from 175 lbs. to 135. "By the end of the movie I just looked like hell," he told Kathie Lee Gifford and Hoda Kotb on Today.
10 of 10
I LOST 21 PERCENT BODY FAT
John Krasinski is yet another actor who took his workouts to a whole new level in the name of performance. He shed 21 percent of his total body fat over the course of four months to portray an elite Navy SEAL in 13 Hours: The Secret Soldiers of Benghazi. The actor, who told Stephen Colbert he "couldn't do one pull-up" before training, turned to fitness guru Jason Walsh to get into flawless shape. "I gotta be honest: It was brutal at times," the star admitted to Men's Health about his twice-a-day, five-times-a-week workouts. "We did tons of metabolic work, dragging sleds and all this stuff I've seen NFL players do." While the rest of the world was impressed by Krasinski's newfound beefcake status, his wife Emily Blunt was … not. "She hates it. She would way prefer to have doughy guy back," he joked on The Late Show.
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