Mark Wahlberg doesn’t do anything by halves when it comes to preparing for his movies.

The actor spoke to Jimmy Fallon on Thursday’s “Tonight Show” about having to consume 11,000 calories a day to play a boxer-turned-priest in his new movie “Stu”.

As Fallon shared side-by-side photos of the three-week transformation, Wahlberg said: “Unfortunately, I had to consume, for two weeks, 7,000 calories, and then for another two weeks, 11,000 calories. And it was fun for about an hour.

“It’s such a hard, physical thing to do. Losing weight, you just kind of tough it out, you just don’t eat, and exercise. And this, even when you’re full, I would wake up after a meal and have another meal. I was eating every three hours. It was not fun.”

Fallon pointed out that Wahlberg had recently turned 50, with him asking if gaining and losing weight for a role had got harder with age.

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“Yeah, absolutely,” Wahlberg replied. “Once the metabolism starts to slow down, it gets really difficult. I was trying to get this movie made for six years, we only had 30 days to shoot it, and so I wanted to really make it happen.

“And [I] was also crazy to have financed a lot of it myself. So I knew I was on a ticking clock on my own dime, and you get things done pretty quickly when that’s the case.”

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Wahlberg was a bit more excited about gaining 30 lbs in six weeks when he spoke to Jimmy Kimmel three months ago.

“They want me to do it as healthy as possible,” he previously shared.

“I’m like, ‘Dude, I’ve been on such a regimen for so long, I just want to eat everything in sight.’ I want to go to bakeries, I want to go to Denny’s, I want to get pancakes. I want to get everything that I could possibly get my hands on.”