Well..if he can go onto become a better actor than he is as a musician, fine by me. Christian Bale literally stopped eating for that role. I'm almost sure 50 would have had to stop eating as well. I remember reading about Matt Damon's transformation for Courage Under Fire (where he played a skinny, flashback-afflicted Gulf War veteran), and he ran 12 miles a day (6 in the morning, another 6 at night) and basically ate crackers and cooked chicken breasts.