Matt Damon fun while working on his new dark comedy because he could binge on junk food and skip his usual workout sessions.

The 38-year-old Oscar winner had to bulk up an additional 30 pounds to play bipolar whistleblower Mark Whitacre in the upcoming film The Informant. He also dons a handlebar moustache, a wig, and thick ’80s glasses to add to his unflattering look to make his look complete.

Matt gorged on McDonald’s and Doritos to help him gain weight.

“It was very, very easy to gain weight. It was very, very fun, probably the best time I had working because I didn’t have to go to the gym after work and I just ate everything I could see.”