Matt Damon has revealed that he was Mr. Grumpy on the set of new sci-fi blockbuster Elysium because he was on a strict diet to stay in shape.
The 42-year-old underwent a tough fitness regime to get in shape for the movie and admitted giving up treats left him unapproachable.
Speaking to US Weekly, Damon said: ''I was grumpy on this set, because I was on a diet for the whole movie. I think I shut up a little bit and keep to myself.
''It's not even that it was as extreme as diets I've done before, but it's like, at my age, I want to eat everything in my path, you know what I mean? I think I've become more of a glutton. It was really hard because I love to eat and I love to drink.''
Matt, who has four daughters, Alexia (14), Isabella (six), Gia (four)and Stella (two), with wife Luciana Barroso, previously revealed his wife doesn't mind when he changes shape for movies because she ''likes the variety''.
He said: ''I'm at the point in my life where somebody was silly enough to marry me and won't leave me if I put on a few pounds.
''I think my wife likes the variety. When I did The Informant, I put on 40 pounds. I was like, 'You like this guy, too, don't you?' I'm trying to talk her into that guy. That's the guy I'm most comfortable being.''
