Healthy green shakes were in, pizza was out -- no matter how much everyone around him seemed to savor its gooey goodness every day.
But Kevin James was preparing for "Here Comes the Boom," in which he plays a biology teacher who moonlights as a mixed-martial-arts fighter to save his high school's music program and beloved teacher.
No, they didn't copy the homework of "Warrior," a drama starring Joel Edgerton as a high-school teacher who returns to the MMA ring to rescue his home from foreclosure. That movie also featured Tom Hardy as his brother and Nick Nolte as the men's estranged father.
"We shot this movie a year and a half ago; we knew nothing about them. As I heard the similarities, I was like, are you kidding me? He's a schoolteacher, too?" James said in a recent phone call from a publicity stop in Philadelphia.
"I saw 'Warrior' and I loved it. I thought it was fantastic, but it's dramatic and ours is a comedy," said James, whose "Paul Blart: Mall Cop" beat Seth Rogen's "Observe and Report," also about a mall cop, to theaters by three months in 2009.
"Here Comes the Boom," now in theaters, demanded much more than mastering a Segway at the mall.
"I've trained a little bit here and there my whole life in martial arts, but about 14 months out, we started really getting intense with a lot of the UFC fighters and trainers," the "King of Queens" star said.
"I changed my diet for this and was drinking green shakes, and it was horrible, but it was a lot of work and a lot of sparring and working out and lifting and running, and it was everything you can imagine to get in shape for this movie."
That really is James whose face is turning reddish-purple as a ring opponent clamps his head in a lock. In fact, he's the one getting beaten up, in the service of an inspiring story.
"As far as the fighting went, everything I pretty much did. I've seen those movies where you can slow it down and you can see it's not really the guy there or they cover up. This was such a passion project for me, I wanted to be able to do everything myself." Sometimes more than once, until they got it right.
"I got punched a lot in the face and accidentally banged up, but nothing too bad overall, which was really surprising to me. ... Once the camera started rolling, they were pretty intense fight scenes."
In fact, the Ultimate Fighting Championship gave its blessing after trying to ensure the project was as realistic as possible. It didn't want to endorse the notion that anyone could walk in off the street and climb into the octagon to fight; that's why James' teacher, Scott Voss, is a former college-wrestling champ.
Henry Winkler, with gray hair curling to his collar, portrays the inspirational music teacher who is in danger of losing his job unless Scott makes good on a promise to raise $48,000.
"I met him through Adam Sandler," says James. "We were looking for this character. It's so important to cast this guy correctly because he's the catalyst of my self-sacrifice. If it's a guy you really don't buy and believe I would sacrifice, literally, my life for, the whole story collapses."
Winkler spoke, affectionately, at the 2010 ceremony where Sandler -- his co-star from "The Waterboy" and "Click" -- received a star on the Hollywood Walk of Fame.
"I've always been a fan of his, from 'Night Shift' and 'Happy Days,' obviously. But when I met him, he was the nicest guy I've ever met."
"Here Comes the Boom," which takes its title from the P.O.D. song "Boom," is all about passion. James' biology instructor initially is content to show up late, read the newspaper at his desk and inform a student that the chance she'll ever use anything from his class is ... zero.
All of that changes, however.
Students fight for their orchestra and music teacher, Scott's brother struggles to rekindle the spark of his marriage and work life, and immigrants pursue their dream of American citizenship through a prep class Scott teaches.
"It's all that theme, and it has a ripple effect and everybody kind of affects everybody else. That's really the meaning of the movie."
MMA is a stand-in for obstacles everyone faces.
"We chose this crazy thing to show how far this guy would go, but I've been a big, big fan of the UFC, I'd always been a big fan of it. ... You think it's guys who just hate each other that go in there to battle, and it's not. You see them hugging, they know each other, they know each other's families, they go on vacations together, a lot of them."
The 47-year-old husband and father of three, who speaks for Frankenstein in the animated hit "Hotel Transylvania" with Sandler voicing Dracula, is looking at doing "Valet Guys" with Kevin Hart.
It would be another common-man comedy. "I always used to joke, you know what, I'm the same as everybody else, I'm still the same guy. I have my assistant put my pants on one leg at a time."
James works on not being out of touch with the sorts of TV watchers or moviegoers who might gravitate to a project with his name attached. "I still have the same friends I had growing up and really try to do the same things. Sometimes, yes, you get nicer treatment here or there and you may get a better seat at a restaurant.
"I'm not really in the Hollywood scene. I've never been that guy. You just got to realize how blessed you are and how lucky you are, and it's nice to be able to stay in touch with that because I want to be that common guy, the everyday man who can bring people through the journey of being an everyday guy, a teacher, working his way through the UFC."
James also jokes that he should enjoy his celebrity because there will come a time when people won't be excited to see him. "I'll be just looking for it, going, 'Hey, you guys want an autograph?' 'No, we're good. We don't know who are you.' "
That's not the case now. He's still the stand-up who was a newcomer who met Sandler at a New York comedy club in 1989 or '90 and made mention of it in his journal. In those days, he kept notes on every set and such details as "drove to Poughkeepsie and did a show for $20."
"I remember writing, 'I met Adam Sandler tonight,' and he said I'm going to make it in this business and he was really nice and supportive to me." He did make it, and Sandler has been supportive -- and James has returned the favor.