How Khris Davis Gained 50 Pounds to Become ‘Big George Foreman'

Khris Davis didn't take his role in "Big George Foreman" lightly.

In fact, he took it quite heavily.

The movie follows the titular character stepping back into the boxing ring after a lengthy retirement. Foreman was an Olympic gold medalist and heavyweight champion in his heyday, and he reclaimed his title status once he returned to the sport.

Foreman underwent a dramatic physical transformation between his two boxing stints, and Davis did the same while filming the new movie.

Davis told NBC that he went from 225 pounds to 280. While the film's studio was prepared to help him appear heavier on screen, Davis was committed to actually adding the weight.

"They had called me and said, 'Hey Khris, we were thinking of making a fat suit for you,'" Davis said. "And I said 'Here, give me five weeks. Come back in five weeks, see my body and if you see my body and you still think I need a fat suit, fine. But before you get that fat suit, let me show you what I can do.'"

Davis went on to gain 50 pounds in those five weeks and was up to 280 within eight weeks. He said he was able to pull off the dramatic change by eating 7,000 calories a day.

"I ate all day," he said. "So I would eat a 1,200-calorie meal and all day I'm snacking on 700 calories here. It would be like I would stop snacking, and a half hour later I'm drinking a protein shake that's 700 calories. And then an hour later I'm eating another 700-calorie snack. And then an hour later I'm going back to a 1,200-calorie meal."

Davis didn't just want to put on weight, though -- he wanted to put on weight that wouldn't become permanent. He stuck to a non-dairy, non-sugar diet during the process and was able to pull it off.

"I was down to gain the weight," he said. "What I didn't want the weight to do was to stick, so I wanted to do it as clean as possible."

The commitment to eating 7,000 calories per day got harder and harder for Davis.

His solution? Stop eating and start drinking.

"I wasn't able to put food down at one point, so I would have to chew my food and drink water to trick my body into thinking that I was drinking rather than eating. … Sometimes it would take me two hours to get down one plate of food, but by that time, I had to eat my 700-calorie snack, so I'm just shoving food down my mouth non-stop."

As if managing the weight wasn't difficult enough strictly from a food perspective, there was another major hurdle: boxing.

To properly embody Foreman, Davis spent around half his day training and had to make sure the rigorous cardio didn't shed the pounds he was working hard to put on.

"If you're throwing punches for 12 hours a day, you're going to lose a lot of weight," he said. "You can lose 10 pounds just sweating it off that day. So I had to manage my weight that way while filming, while training."

Davis' full body of work will be on display when "Big George Foreman" opens in theaters on Thursday.