Chris Pratt’s body likes to go method.

In his appearance on Conan on December 18, the Parks and Recreation star opened up about his weight loss and subsequent gain for two back-to-back movie roles.

“I don’t know if you can tell from the angle right now, but I’m kind of a fat ass. I have a little extra belly,” Chris joked, revealing that the lingering pounds were for the movie Starbuck, in which he plays a “despondent, emasculated character who’s fat and unhappy.”

“I’ve always been a little soft. I like to eat,” he admitted. “But I had a deadline to play a Seal Team 6 member [in Zero Dark Thirty], so I had about five or six months and I really busted my ass to get in good shape. And then after I wrapped the movie, almost immediately I gained, like, 60 pounds to play a role in another movie [Starbuck].”

Watch the video to see his dramatic transformation from hunky to chunky!

Credit: YouTube Photo: Chris Pratt Reveals Weight Loss and Gain on Conan on December 18, 2012 (VIDEO)