Pain and Gain: Actors who have bulked up for movie roles

If you noticed anything physically different about actors Mark Wahlberg and Dwayne Johnson in the first trailer for Michael Bay’s comedic crime caper “Pain & Gain,” it’s probably because the pair packed on the pounds in a major way in order to play a duo of hulking body builders in the film.

Wahlberg reportedly gained around 40 lbs. to play fitness-obsessed extortionist Daniel Lugo, training for two months and gorging on up to ten high-calorie meals a day. All that eating and hitting the gym transformed the 41-year-old actor from his regular weight of 165 lbs to more than 205 lbs. In the film, Wahlberg’s character reportedly abuses steroids to bulk up, but the actor’s reps recently had to defend against charges that he “juiced” for the role.

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Wahlberg’s co-star Dwayne Johnson also packed on some major muscle for “Pain & Gain” -- and for the already jacked actor/wreslter, that's really saying something. The 6'4" action star, who admitted to experimenting with performance enhancers in his college football days, looks enormous even by his already gigantic standards. The actor formerly known as “The Rock” has talked about his aggressive workout routines and massive diet in the past, but it’s likely that he had to increase both for his role in the Michael Bay film. No word on just how much extra weight Johnson added, but one look at this comparatively slimmer photo from just a few years ago indicates that it was probably in excess of 50 lbs.

Chris Pratt's before and after shots.

Johnson and Wahlberg aren’t the only Hollywood stars bulking up for roles in upcoming films. “Parks & Recreation's” Chris Pratt went from happily doughy to super fit in order to play a Navy SEAL in Kathryn Bigelow’s upcoming Osama bin Laden hunt movie “Zero Dark Thirty.” Pratt, who has since let himself go for another role, showed off his before and after photos this week on “Conan.”

Tom Hardy in "Bronson."

It’s not unusual for actors to physically change themselves for a role. Such transformations not only help the actors better inhabit the characters, but can also earn them acclaim for their dedication to their craft. Previously slim model-turned-actor Tom Hardy (“The Dark Knight Rises”) bulked up for the role of notorious prison inmate Charles Bronson in Nicolas Winding Refn’s “Bronson,” putting on more than 42 lbs. to play the ultra-violent criminal. Hardy hasn’t looked back since, either, having since played the equally physical roles of a Mixed Martial Arts athlete in “Warrior” and the imposing villain Bane in the most recent Batman movie.

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Robert De Niro, Renee Zellweger, George Clooney, and Matt Damon.

But it’s not always about building muscle for a movie part. Many actors have purposefully made themselves a little pudgier to play certain characters. After getting himself into fighting shape, Robert De Niro famously gained almost 70 lbs. (of fat, not muscle) for his Oscar-winning turn as aging boxer Jake LaMotta in Martin Scorsese’s “Raging Bull.” Slender Rene Zelwegger added nearly 30 pounds each time to play lovelorn Bridget Jones in “Bridget Jones’ Diary” and its sequel. And “Ocean’s Eleven” pals George Clooney and Matt Damon went on a fast food diet to play stocky characters in “Syriana” and “The Informant,” respectively.