Tom Hanks had to gain weight for the first half of Cast Away, and then during a year long break in production, he lost 55 pounds to portray a man who has been stranded on an island for years. He started on a very strict diet – fish, vegetables, very little carbohydrates, and only water. He would also do all types of cardio for about 2 hours a day, 6 days a week.
He was nominated for an Oscar for the role but has been vocal about never wanting to lose extreme amounts of weight in the future. He was recently diagnosed with Type 2 diabetes, and doesn’t think his fluctuating weight did him any favours.
Hanks’ willingness to lose weight already helped him win an Academy Award for playing a lawyer dying of AIDS in Philadelphia.