The 36-year-old actor had to shed 63 pounds (29kg) for his role as a paranoid insomniac in The Machinist, then went on to lose 30 pounds (13kg) to play a drug-addicted retired boxer Dicky Eklund in The Fighter, but insisted that the whole weight loss process is 'horrible'.
He told Empire magazine, 'I've had no training, I'm not method or whatever, so I just do whatever feels right...
'To be honest, I find it laughable that it's considered some f**king gimmick - it's so patronising. For God's sake, do people not understand what a pain it is to do? 'It's as though it's some comment about, 'Oh, it's easy for him, because he's done it a bunch of times.' It's not easy, it's not fun - it's horrible.'