Matt Damon gained 40 pounds for The Informant, but now he’s got to shed the weight — fast, IN TOUCH WEEKLY reports!

MATT DAMON’S PANIC TO LOSE WEIGHT

“Matt has to lose it to do reshoots for Green Zone,” his Informant co-star Joel McHale recently said. In the movie, Matt plays a fit military officer and “the reshoots are in the next couple of months,” says an insider. But Matt, 37, isn’t stressing. “He plans on running five miles a day outdoors and on the beach,” his pal says. “He’ll eat zero carbs, lots of tuna, chicken and almonds — his favorite snack.” Matt packed on the pounds for The Informant by eating “a lot of In-N-Out, a lot of burgers, a lot of beer.” Matt filmed scenes for Green Zone in London in early April.

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