11,000 calories a day will do that to ya.

Mark Wahlberg can certainly appreciate a good cinematic physical transformation. But the actor, who regularly chronicles his fitness journeys on social media, tells EW his weight gain for Father Stu took a significant toll on him.

In director and writer Rosalind Ross's latest film, Wahlberg play Stuart Long, a bad-boy amateur boxer whose career is destroyed due to an injury. When he moves to Los Angeles in pursuit of stardom, he ends up falling for a Catholic Sunday school teacher. Coupling his budding relationship with the aftereffects of a devastating motorcycle accident, he sheds his agnostic beliefs and sets out to become a priest.

"I put on 30 pounds and went from being a guy who was in fighting shape to a guy who was wheelchair-bound, suffering from a rare muscular degenerative disease," Wahlberg explains. "I was just turning 50 by the time we finished the movie, and I was eating 11,000 calories a day. That drastic weight gain really took a toll on me over the course of the last seven, eight months."

Mark Wahlberg Instagram post about weight gain for Father Stu
Mark Wahlberg says his 'Father Stu' weight-gain transformation 'really took a toll' on him.
| Credit: Mark Wahlberg/Instagram

Wahlberg shared before-and-after photos from his experience on social media back in May 2021. He then talked about his rocky metamorphosis with Jimmy Fallon on The Tonight Show that following July.

"Even when you're full, I would wake up after a meal and have another meal," he said. "I was eating every three hours. It was not fun."

What exactly was he eating? "I tried to do it in a healthy way," he told E! this year. "It was a dozen eggs and a dozen pieces of bacon, two baked potatoes, a Porterhouse steak, two bowls of white rice, and a glass of olive oil. The first two weeks were high proteins. The second two weeks were a lot of carbs. The last two weeks starches and then sodium, just to kind of get as bloated as possible." But he toughed it out for the sake of the movie, which he spent years trying to get off the ground.

"I do like having to prepare physically as well as mentally," Wahlberg tells EW. "That's always ideal. You kind of say, 'Okay, I got this movie coming up three, four, or five months, however long I have to prepare. Let me start now.' And I become a little bit obsessive about it."

Father Stu opens in theaters April 13.

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