Jason Segel – 35 Pounds
Jason Segel’s most famous role might have been on the show How I Met Your Mother, but the actor went through a pretty dramatic transformation for another one of his roles. The president of Universal Pictures, Ron Mayer, actually requested that Segel slim down when he was cast in the movie, The Five Year Engagement. The 39-year old then lost 35 pound with the help of a trainer, who helped him follow a strict diet and guided him through 2 workouts daily. Segel could also use online classes in dieting if it is still needed.