How Did Mark Wahlberg Lose 60 Lbs. for His New Film The Gambler?

11/11/2014 at 10:44 AM ET

Mark Wahlberg is no stranger to transforming his physique for his diverse film roles. His latest test? Losing 60 pounds to play college literary professor and high-stakes gambler Jim Bennett in December’s The Gambler.

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“I appreciate when I have an opportunity like this so there isn’t anything that I wouldn’t do to prepare, whether it be mentally or physically,” Wahlberg told PEOPLE at the world premiere of the movie at AFI Fest 2014 in L.A. “I mean, that’s what the job requires. That’s what you’re supposed to do and I welcome those things with open arms. And I usually get a little obsessive.”

Despite his unwavering ambition, dropping 60 pounds to play this character was no easy task. So how did he do it? “A liquid diet for six weeks. Jumping rope. Not eating. Being miserable,” Wahlberg shared.

Wahlberg also set his own standards really high to help maintain his focus.

“My goal really was to get a pound thinner than I got in Boogie Nights, which was at 25 so it was a lot easier then than doing it at 42,” he explained.

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And even though the actor dedicated himself to his physical transformation, he confessed that getting into the mind of the character was even more challenging.

“I was more focused on understanding the words that I had to speak in the classroom,” he explained. “Being able to believe in myself going out there and saying those words and feeling confident.”

What do you think of Wahlberg’s weight loss? Are you excited to see the film? Share your thoughts below.

–Abby Stern