Filming 2010's horror film Black Swan took a lot out of the movie's stars, Mila Kunis and Natalie Portman. "My prep was a lot of dancing and very little eating - which I know you're not supposed to say, but it's the truth," Kunis explained in a joint Vogue interview with Portman published on Friday, August 15. "I drank a lot of broth and danced for 12 hours a day." The That 70's Show actress was 27 at the time of filming.