The 'Wolverine' star stuck to a rigid diet and fitness regime to get in shape for the blockbuster and his wife Deborra-Lee Furness believes he is the "world's most disciplined man" and that his gruelling
routine helped him get into character for the movie.
Asked what he did after completing the movie and the other 'X-Men' films, Hugh exclusively told BANG Showbiz at the film's UK premiere at Empire Cinema in London's Leicester Square on Tuesday night: "Eat! Oh my God. I eat embarrassing amounts of crap. I eat embarrassing amounts of bad food."
Deborra, who joined him on the red carpet, added: "I think that's where he finds his rage [for the character] - you don't give him nice food ... really scary! He's really scary with no food. Wolverine rage!
"It takes a lot of discipline. I'm there to witness it. The world's most disciplined man."
Hugh, 44, also insists that he still enjoys getting in tip-top shape for movies even though he complains about it.
He said: "I'm enjoying it more than ever. I think being a little older helps with this character, because he's like 200 years old. But I complain about it [on set]. At four o'clock in the morning I'll whinge... I'm horrible!"
The Australian couple were joined at the screening by the movie's other stars including Famke Janssen, Tao Okamoto, Rila Fukushima, Will Yun Lee and director James Mangold.