Hunger star Michael Fassbender got extremely thin for his role in the move - SO thin, people thought he had cancer.
His diet consisted of just 600 calories a day over a 10-week period.
"I had my cut-off point and if I went below it I was told things would get a little tricky. I remember looking at myself and thinking, 'God, there are bones sticking out here'. I went for my final check-up after filming and my doctor said, 'Last time you came in here you looked pretty bad. My assistant was outside and she saw you and said, 'My God, that guy's really ill, isn't he?' She thought you had cancer'. People don't actually say anything directly to you."
The weight-loss experience was a bit "liberating" for Michael when he lost his sex drive for about six weeks. He added:
"My libido disappeared for about six weeks. It felt very liberating. You don't realise how distracting all that stuff can be. Your body streamlines and focuses on what's important. I suppose that's why monks and religious people do it."