Traditionally chubby Tom Hanks is by no means overweight, but one might call him just a little husky. Of course, no one could accuse him of raiding the candy store after seeing the movie "Cast Away." Hanks dropped about 50 lbs in order to correctly portray a shipwrecked FedEx employee. In fact, the crew had to start filming with Hanks in regular shape, and then stop filming so that Hanks had enough time to lose the weight. The crew filmed Harrison Ford's "What Lies Beneath," and then picked up when Hanks had lost the 50 lbs.
3. Daniel Day-Lewis
Daniel Day-Lewis is known for his complete dedication to the roles that he plays, but he took that dedication to a whole new level when getting ready to play Gerry Conlon in "In the Name of the Father." In fact, along with a 30-lb weight loss to get in the zone, Day-Lewis also asked to sleep in a jail cell and be verbally berated by crewmembers to completely get in character for the part of an IRA prisoner. It probably explains why Day-Lewis only does a few movies every couple of years; having crewmembers yell at you for hours each day doesn't actually sound that pleasant, regardless of how much you're getting paid.