Christian Bale lost about 70lbs in 3 months for the Machinist

Charlie Sheen built muscles for Hot Shots! Part Deux

Russell Crowe gained 63lbs for Body of Lies

Jake Gyllenhaal gained 25lbs of muscle for Jarhead

Ben Stiller build some muscles for Tropic Thunder

George Clooney gained 30lbs of fat for Syriana

Linda Hamilton toned up really well for Terminator 2

Hilary Swank put on a lot of muscle of Million Dollar Baby

Mr. Stallone put on about 40 lbs of fat for Copland

Tom Hanks lost about 50lbs for his movie Cast Away

Renee Zellweger gained a lot of weight for both Bridget Jones movies

Demi Moore gained muscle for G.I.Jane doing one arm pushups

Jessica Biel gained some really defined muscles for Blade Trinity

Matt Damon lost 40lbs for Courage Under Fire

Gerard Butler gained muscle for 300

Ed Norton (yeah the skinny dude) gained muscles for America History X

Eric Bana Ballooned up for his role in Chopper

Ryan Renolds packed on some serious muscle for the Blade movies
