Talk about a body of work! Some actors bulk up, slim down, or pack on pounds all in the name of art - or a shot at winning Oscar gold. This year's Best Actress Natalie Portman shed 20 pounds from her already petite frame to be en pointe as a ballerina in Black Swan. Meanwhile, Christian Bale nabbed a Best Supporting Actor for his downright skeletal appearance in his portrayal of a drug addict in The Fighter. (This portrayal is only rivaled by his appearance in The Machinist in 2004).
These two actors are certainly not the first (nor the last) to undergo extreme body makeovers. Here, from our friends at Fitbie.com, is a look at some of Hollywood's most celebrated shape-shifters.