Jake Gyllenhaal: I’ll get fat when I finish Prince of Persia

Jake Gyllenhaal has joked that he’s going to get fat when he finishes filming Prince of Persia.

The Donnie Darko star transformed his slight frame and gained more than five pounds of muscle for the big-screen version of the popular video game.

He told Entertainment Tonight recently: “I guess I’ve gotten buff. I over-prepared myself because I never knew how much they were going to ask me to do. So I just made sure I’d be hopefully able to do anything.

“There’s a lot acrobatics in the movie - a lot of running up walls, and jumping on things… so it requires muscularity, but it requires a lot of aerobic ability too.”

But he’s not convinced he’ll keep it up once filming finally wraps: “It’s going to turn into fat, and I’m going to be happy.”

Jake spent eight weeks filming in the Moroccan desert over the summer but is now filming studio scenes outside London. The film is scheduled to hit cinemas in 2010.