13. Ryan Reynolds
Similar to Bradley Cooper, Reynolds started out on TV acting in series until he landed a role in National Lampoon’s Van Wilder: Party Liaison. At the time he was the funny skinny guy, but two years later he landed the role of Hannibal King in Blade: Trinity. For that movie, he gained 25 pounds of lean mass by eating 8-10 meals per day, then training six days a week. Between movies Reynolds has maintained an active life, transforming himself again for roles like Deadpool.