The 44-year-old Australian actor takes on the role of Jean Valjean in the big screen adaptation of the hit musical and he said he had to go to extreme measures to look like a starving prisoner at the beginning of the movie, reported Contactmusic.
"I had to lose a lot of weight, so I went on a very strict diet. I even went without water for 36 hours before I filmed the opening scene. And then after that, I put on weight.
I was training every day," he said.
In the movie, 'Gladiator' star Russell Crowe plays Valjean's arch-enemy, Javert, and Jackman said he loved every moment of working with Crowe, especially as they have a lot of history together.
"I've known Russell for years. If you ever go to a party thrown by Russell you end up singing so we had a lot of practise! But it was great working with him and he's one of the world's greatest actors. I love him."