Robert Pattinson doesn't think his abs are as good as his 'Twilight' co-star Taylor Lautner's.

The 25-year-old actor started eating calorific treats such as chocolate and cheeseburgers when he found out his body shape did not compare to the 19-year-old hunk during filming for 'The Twilight Saga: Breaking Dawn - Part 1'.

He told MTV News: "During [filming in] Brazil, the day before I had to do my shirtless scene, I realised [my abs] weren't as good as Taylor's, so I just ate every bit of chocolate in the mini-bar. I started eating cheeseburgers and stuff."

And he joked: "This is so unfair doing a comparison. Everyone says I painted on my abs in ['New Moon'] - I did not! Taylor has his painted on too!"

Robert and his girlfriend co-star Kristen Stewart went "nuts" trying to get in shape before filming 'The Twilight Saga: Breaking Dawn - Part 1', which is out on November 18, and he even stopped eating sweets and drinking alcohol.

He added: "Yeah, I didn't eat any candy and I didn't drink any beer for a while.

"I went kind of nuts. Me and Kristen went nuts working out, because we hadn't worked out for any of [the previous films]."