Hugh Jackman has opened up about the gruelling training process he underwent to turn himself into a gaunt prisoner for Les Miserables.

And while much has been made of Anne Hathaway's physical transformation for the film, it seems Jackman was also working hard to transform his body.

The Australian actor, who plays Jean Valjean in Tom Hooper's musical, explained to Vulture: "Weirdly, this was almost more physical in a way than an X-Men movie!"

"I was spending even longer in the gym - like three hours in the gym - because I needed to be as emaciated as possible, but still keep some muscle on for Jean Valjean."

The 44-year-old added: "I had to eat seven times a day with no carbohydrates, but then you had the exercise.

"I'd wake up and do 45 minutes of [cardio] on an empty stomach, eat something, go to the gym, do a vocal warm-up, and then after lunch I'd go back to the gym again. Otherwise, I'd just become skin and bones."