JUDE Law says drinking "ten Coca-Colas a day" to gain weight for his latest movie was "amazing".

The actor stars in Dom Hemingway and gained almost 13kg to play the title role in the BBC-produced film.

Law - who plays a bloated, balding petty criminal back on the streets of London after being released from prison - says he thoroughly enjoyed eating and drinking whatever he wanted in order to transform himself.

"[Drinking] ten Coca-Colas a day, [was] amazing!" he exclaimed to The Telegraph.

"Oh, it was a joyous role to take on. Because I am at a stage in my life where I'm panicking a bit. 'Ooh, am I going a bit bald? Am I getting a bit…?' You can't help doing that in your late 30s, can you? When you realise that you're no longer the 21-year-old you used to be. So playing someone who was letting it all go was really liberating."

Since filming wrapped the 40-year-old has lost the excess weight and joked that his confidence was boosted as he started to look more like himself again.

"Now that I’ve lost the weight and my receding hairline isn't quite as bad as we made it look for the part, I can look in the mirror and think, 'Oh, it’s not that bad! I’m still looking all right, actually!'" the Sherlock Holmes star laughed.

Known for his handsome looks, the Brit has often been cast as the stereotypical heart-throb in the past, including films such as The Holiday, Alfie and Closer.

Now he has started to age the star has won a wider variety of roles and says his changing appearance is something he is embracing.

"Certainly, yes, in the last couple of years, I have felt a freedom, which has been very fulfilling", Law admits, adding that since turning 40 he has revaluated himself as a person.

"It feels like a very real time to take stock and make changes for the right reasons".