Matt Damon loved being able to eat whatever he wanted for his latest movie.

The Hollywood actor had to gain 30lbs for his role as whistleblower Marc Whitacre in 'The Informant' and says it was a very enjoyable part of his job.

He said: "I thought it was a blast and my wife liked it when I paraded around with my belly hanging out. And actors don't usually get to eat just what they want, but for this film I'd be at home all day drinking beer and eating pizza. My wife would walk in and look at me stuffing my face and I'd just go, 'Hey, I'm working here!' "

Although he enjoyed gaining the weight, he admits it was lot more difficult to shed the extra pounds.

He said: "All I did was eat like I ate when I was in college and it came on shockingly fast. Losing it was not any fun."