British actor Rufus Sewell has become hooked on 'The Rock' diet after using it to help him bulk up to play Autolycus in Dwayne Johnson's new epic Hercules.

The Dark City star asked his leading man for tips on how to pile on the muscle and has now become a fan of The Rock's tough bodybuilding diet.

He says, "We were all eating our own versions of the Dwayne Johnson diet. I mean, f**k me, I was so sick of salmon by the end of that job. But now I've become institutionalised, I can't get off it! I've got a protein habit that I just cannot keep under control."

But Sewell admits he could never hope to become a man-hulk like Johnson: "No matter how much you work out, it's quite easy to develop dysmorphia because if you stand next to Dwayne Johnson, you're always going to look like there's not enough going on.

"I was standing next to Dwayne every day thinking, 'My arms are so spindly'. It was only when I got home I realised none of my old suits fitted me."