Tom Hanks, Castaway
The actor had to put on 50 lbs (23 kg) during pre-production to make him look like a middle-aged man. When Tom Hanks was in this shape, they shot the parts of the film before the island scenes, and then took a year off to let Tom lose weight to impersonate a real cast away. He didn’t shave or cut his hair for weeks and shed 55lb in four months with a diet and a tough exercise regime.