Chris Pratt Recalls Feeling "Impotent, Fatigued, Emotionally Depressed" When He Weighed 300 Pounds

"I had real health issues that were affecting me in a major way," he tells Men's Health U.K.

When Chris Pratt started taking care of himself, the rest took care of itself.

The actor's weight yo-yoed for years, after he packed on the pounds for NBC's Parks and Recreation. "I saw myself in an episode, and in the matter of two moments very close together, I thought, 'Oh my God, I'm getting fat,'" Pratt, 35, recalls in Men's Health U.K.'s July issue. "And then almost immediately I did something else and I thought, 'Holy crap, I've never seen myself funnier.' And I put the two together."

Pratt had voluntarily gained weight for his role on the hit TV show, which ended earlier this year after seven seasons. "I said to the creators that I wanted to get fatter for the role. They loved it. I announced it to the whole cast, and then it became a bit of a game: how fat can I get and how fast can I get that fat," the actor remembers. "I would eat three or four cheeseburgers at every table read."

At his heaviest, Pratt weighed 300 lbs.

Gaining weight was easy. Losing it was hard.

When he slimmed down for his role in 2011's Moneyball, Pratt "lost about 35 pounds" in six weeks. "I ran five or six miles a day. I ate leafy green salads and protein shakes. I cut out all alcohol. Trim, trim, trim," the actor says. "Finally I sent them a photo and it was, 'Hey, they want to see you again.' Yes!"

He got ripped for his role as a Navy SEAL in 2012's Zero Dark Thirty, but he gained the weight back for Delivery Man and Parks and Recreation. But after seeing a screening of Zero Dark Thirty, he wanted to make a change. "I'd gone back and forth, lost weight for Moneyball, got fat again, then trimmed down for Zero Dark Thirty, then gained it all back again for Andy. That's when I saw Zero Dark Thirty and right after walking out I was like: 'I'm going to get in shape and I'm never going to be fat again,'" Pratt recalls.

The actor stayed true to his word and appeared even more muscular in 2014's Guardians of the Galaxy. "When I was fat and unhappy, the only moments of respite I got was when I was eating. Now mealtimes are sometimes lame, because that's the way it can be when you're eating healthily. But all the time between meals, I feel great," says Pratt, who next appears in Jurassic World. Regarding the downside of being fat, he tells the magazine, "I was impotent, fatigued, emotionally depressed. I had real health issues that were affecting me in a major way. It's bad for your heart, your skin, your system, your spirit."

The full interview appears in Men's Health U.K.'s July issue, on stands now.

The magazine is available as a digital edition.