8 actors who transformed their bodies for roles

From bulging muscles to skin and bones, the physical metamorphosis of Hollywood stars is an art all its own.

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Chris Pratt in 'Guardians of the Galaxy' Chris Pratt in 'Guardians of the Galaxy' (Photo: Guardians of the Galaxy)

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Chris Pratt for 'Guardians of the Galaxy'

In only six months, American actor Chris Pratt went from a goofy pudgy guy on the sitcom "Parks and Recreation" to a ripped action star in "Guardians of the Galaxy."

The new Star Lord says he dropped more than 60 pounds for the role through a combination of workout regimen P90X, running, boxing, swimming and kickboxing. “Three or four hours a day of just consistent, ass-kicking hard work,” Pratt told Men's Fitness.

In addition to the exercise, Pratt also revamped his diet – increasing his intake to 4,000 calories per day and drinking lots of water. "I was peeing all day long, every day. That part was a nightmare," he added.

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