Celebrity Transformations for a Role

Chris Messina gained 45 pounds for his role in “Live By Night”

Miles Teller bulked up for his role as a boxer in “Bleed for This.”

Mark Wahlberg packed on 40 pounds in two months to play a bodybuilder in “Pain & Gain.”

Robert Downey Jr. gained 20 pounds of muscle for “Iron Man 2.”

Gerard Butler seriously bulked up for “300.”

Will Smith had to really pack on the pounds to play famous boxer Muhammad Ali in “Ali.”

Natalie Portman dropped 20 to play a ballerina in “Black Swan.”

Tom Hanks lost 50 pounds to play a stranded FedEx employee in “Cast Away.”

Renee Zellweger gained 30 pounds twice — to play the title character in “Bridget Jones’s Diary” and “Bridget Jones: The Edge of Reason.”

Ryan Reynolds buffed up to play Nightstalker Hannibal King in “Blade: Trinity.”

Russell Crowe gained 60 pounds for “Body of Lies.”

Hugh Jackman buffed up to play Wolverine in all three “X-Men” movies and the solo sequel.

Christian Bale lost 62 pounds to play an insomniac in “The Machinist.”

Seth Rogen lost around 30 pounds to play The Green Hornet.

Charlize Theron gained about 25 pounds and totally transformed her appearance to play serial killer Aileen Wuornos in “Monster.”

Chris Evans gained about 20 pounds to play the title superhero in “Captain America.”