Movie star Luke Wilson is proud of gaining 18 pounds (8.2 kilograms) to fill his character in new movie The Family Stone, because he is convinced many leading actors would not be prepared to change their physique for a part.

The actor pokes fun at his peers, including Jamie Foxx and Matthew Mcconaughey, because they are too proud of their fine muscle definition to consider taking on a different kind of role.

He says, "It was actually brave of me. I put on about 18 pounds for the movie, which a lot of your younger actors, they're a little too vain to do that.

"Your Jamie Foxxs, your McConaugheys, they could be playing WC FIELDS (portly silver screen icon) and they'd have a six-pack. They're not willing to go the distance."