The "Jurassic World" star has physically transformed from "Parks and Recreation's" lovable overweight goofball to a bona fide action star, and he opened up about his weight struggle in the July issue of UK Men's Health.
The actor reportedly said he became "impotent, fatigued, emotionally depressed" when he was nearly 300 pounds.
Pratt, 35, blamed love and comedy for the increased poundage, saying that he fell for a woman — wife and actress Anna Faris — who "loved to feed her man."
"It was like Momma Bear and Papa Bear. She would eat a little bit, I would eat all of mine and the rest of hers," he said, also comparing himself to Hansel being fattened up to be put on a fire.
His role on the NBC comedy didn't alleviate the issue either because the cast loved the notion of him swelling up for the role.
"It became a bit of a game: how fat can I get and how fast," he said. "I would eat four burgers at every read. I became really fat and got up to almost 300 pounds."
The actor said he had "real health issues" that were affecting him in a "major way."
Though Men's Health didn't elaborate on what they were in the issue's teaser quotes, Us Weekly reported that Pratt said he became "impotent, fatigued" and "emotionally depressed."
"When I was fat and unhappy, the only moments of respite I got were when I was eating. I felt great shoveling food down my neck and totally negative in between," he said. "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."
Pratt slimmed down for 2011's "Moneyball" but gained back the weight for
Since then, he's landed high-profile roles appearing — and disrobing — as the intergalactic bandit Star-Lord in 2014's "Guardian's of the Galaxy" and affable dino-trainer Owen in the upcoming "Jurassic World," which opens June 12.