6. Natalie Portman
It’s no surprise that even petite Natalie Portman was asked to drop 20 pounds before portraying an obsessed ballerina in Black Swan.
To help shed the weight Portman did five to eight hours of ballet, swimming and interval training every day.
This paid off hugely, as the Black Swan was praised by the critics and actually made a lot of money, leaving Natalie with her pockets full and body as firm as rock.