Mark Wahlberg has revealed he’s consuming 7,000 calories a day to beef up for his role in the forthcoming movie Stu.

The actor shared before-and-after photos of his progress over the course of three weeks in which he has visibly lost muscle mass and gained more fat.

It’s all in preparation for his role portraying a professional boxer who becomes a priest named Father Stu.

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Now, Wahlberg’s personal chef Lawrence Duran has told E! Online that the star is eating three times the average amount an adult consumes in a day to bulk up.

The diet is strict and consists of large amounts of protein – and isn’t full of the junk food you might expect for such a task.

Duran said: “His first breakfast is four eggs – that’s the pre-breakfast. Then, he does his workout and then after the workout, which is usually around 5 to 6 o’clock in the morning, we do eight eggs, six strips of bacon, a cup of rice, two tablespoons of olive oil and a protein shake. It’s his protein-inspired mass weight-gainer to help build on a little more muscle as well.

“Then, three hours later, we do some kind of ground beef or ground turkey, whether it’s been made into a hamburger patty or a meatloaf, with another cup of rice. And then, three hours later, I usually do half of a roasted chicken, another cup of rice, I’ll do about a cup of cooked spinach and a cup of cooked beets as well.”

Later, Duran said Wahlberg will eat either an eight-ounce slab of veal or pork and a four-ounce piece of salmon with rice and beets, before his last big meal consisting of “eight ounces of some type of steak, eight ounces of some kind of white fish, like a sea bass or a halibut, and load up on tons of vegetables”.

At the end of the day he eats a mashed-up concoction of porridge, apple sauce, jam, almond butter and molasses as a “mass gainer to put on weight during his sleep”.

According to the trainer, Wahlberg is allowed one “cheat day” per week where he can indulge in unhealthy food such as pizza, cookies and ice cream.

Wahlberg previously told Jimmy Kimmel Live that he was hoping he’d be able to eat fatty meals (“20-piece chicken nugget, hot wings from Kentucky Fried Chicken with a six-pack of beer”) but his team “want me to do it as healthy as possible”.

“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.’”