Matthew Fox
When Matthew Fox took on the role of Alex Cross, aka Picasso, he changed his diet to match that of, well, a serial killer's. He cut out all appetizing food to make him angrier and leaner. He also started a brutal exercise regimen that would have broken the average person...
The Making of a Psycho
Fox's ideal image for Alex Cross was exactly what he wanted him to be like. He told his personal trainer that he wanted to look "menacing." In fact, this look was so iconic that Fox became the victim of a long-term meme storm that took his body in the movie and compared him to things like fences, train tracks, and the alien baby from Alien: Resurrection.