Chris Hemsworth ate just 500 calories a day (far below the recommended 2,000 to 3,000 calories for someone his size) to prepare for “In the Heart of the Sea.” Hemsworth maintained a sense of humor about his struggle, posting the photo at left on Instagram with the caption, “Just tried a new diet/training program called ‘Lost at Sea.’ Wouldn’t recommend it.. #IntheHeartoftheSea.”
Chris Hemsworth / Instagram / Splash News
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Chris Pratt infamously shed pounds and built a whole lot of muscle for “Guardians of the Galaxy.” How? He told Vulture, “Three or four hours a day of just consistent, ass-kicking hard work.”
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Christian Bale lost a whopping 63 pounds to play a chronic insomniac in “The Machinist.”
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Bale told MTV News he didn’t pay attention to numbers on a scale when losing weight to play a heroin addict in “The Fighter” — instead he just ran constantly.
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The transformation Bale probably enjoyed most? Eating cheeseburgers to gain 40 pounds for “American Hustle.”
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The normally beefy 50 Cent shed 60 pounds to play a cancer-stricken football player in “Things Fall Apart.”
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Anne Hathaway lost 25 pounds to play Fantine in “Les Miserables” — 15 before filming started and 10 during — by basically subsisting on oatmeal paste. She won an Oscar for her portrayal, in which she described herself as looking “near death.”
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Charlize Theron put on 30 pounds to play serial killer Aileen Wuornos in “Monster” because her body was too “athletic.” Tough life.
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The normally buff Eric Bana stopped working out and ate whatever he wanted for a month. The result? The cautionary tale that became his body in “Chopper.”
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Gerard Butler was never a slouch, but when he played King Leonidas in “300,” he cut down his body fat and put on 10 pounds of muscle to boot.
Everett Collection; Pacific Coast News
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Hilary Swank trained like crazy to bulk up to a boxer look for “Million Dollar Baby.” While producers wanted her to gain about 10 pounds of muscle, she ended up gaining 19.
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Jared Leto packed on 60 pounds to play John Lennon’s killer, Mark David Chapman, in “Chapter 27.”
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Leto later lost between 30 and 40 pounds for his Academy Award-winning portrayal of transgender Rayon “Dallas Buyers Club.” How? He told The Wrap it was just by not eating.
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For his breakout role in “Courage Under Fire,” Matt Damon shed 40 pounds with a strict diet and running 10 miles every day.
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Damon later happily put on 40 pounds to star in “The Informant.”
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“Lost” star Matthew Fox dropped 40 pounds to play an assassin in “Alex Cross.”
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Matthew McConaughey is usually and infamously ripped, but he lost 40 pounds to play an HIV patient in “Dallas Buyers Club.”
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Michael Fassbender dropped 42 pounds for the aptly titled “Hunger” by limiting himself to 900 calories a day and exercising almost constantly.
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Mila Kunis dropped to 95 lbs. for “Black Swan,” but she didn’t love it. She told Harper’s Bazaar, “When I gained it back, it went to completely different areas. All the weight that left my chest went to my side hip, my stomach … I’d be happy if my ass got bigger.”
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Natalie Portman was always svelte, but she dropped another 20 pounds from her petite frame for her Oscar-winning turn in “Black Swan.”
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Jake Gyllenhaal got jacked for “Prince of Persia.”
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Gyllenhaal later got gaunt for the upcoming thriller “Nightcrawler.”
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Renee Zellweger put on between 25 and 30 pounds to play Bridget Jones in 2001 and then again in 2003, causing the usually bony starlet to look, well, normal.
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Russell Crowe put on 63 pounds for “Body of Lies” by eating burgers for breakfast. Too bad they’re not hiring anymore.
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Seth Rogen slimmed down for his role in “The Green Hornet” simply by watching what he ate and exercising regularly. Who knew it could be so simple?
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Tom Hanks dropped 50 pounds for “Castaway.” He previously lost weight for his role as a lawyer dying of AIDS in “Philadelphia,” but was much more clothed in that film, so the loss wasn’t as visible to audiences.
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Vanessa Hudgens packed on the pounds and chopped off her hair for her role in “Gimme Shelter” in 2013.
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