Kellan Lutz is in prime shape for his upcoming role in Hercules: The Legend Begins. The sexy actor has been enduring a heavy fitness and workout plan to get in shape for the movie, but part of his diet leaves a lot to be desired. Some of Lutz’s diet may also be part of the reason that his version of Hercules may not be as physically big as Dwayne Johnson’s version when “The Rock” takes on that role in Hercules: The Thracian Wars.

Speaking to E! News, Lutz admitted that it was difficult to stick to his diet while filming the upcoming Hercules flick. “If you’ve ever been on a movie set, there’s food all the time,” he said. “It’s hard to stay healthy because I had milk chocolate bars three times a day and I’d just eat the whole bar.” He also laughed about being smaller than Johnson for his role as Hercules, joking that “I wanted to get big…there’s not enough ‘extra-curricular’ stuff for that.”

Kellan Lutz Kellan Lutz admitted that he hasn't exactly been following his Hercules diet to the letter.

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It’s likely that Lutz engaged in much of the same fitness regimen for his previous role in the action flick Immortals. For that movie, he had three sessions per day of functional training that combined CrossFit, boxing, plyometrics and stunt work. He also worked out daily with personal trainer Rich McDonald and began his rigorous fitness workouts each day. “I like to wake up with the sun around 6:30 and go out and meet the day,” he said to Men's Fitness. “I’ll just go for a run, drop and do some push-ups, run some more, do lunges, grab the rings and do pull-ups.”

Kellan Lutz Kellan Lutz partied with Miley Cyrus in Las Vegas.

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However, Lutz was already in great shape before Immortals and his fitness regimen was largely maintenance.  “Gods in movies are usually these old guys, but my take was if you lived forever, you’d want to look young and fit forever,” said Immortals director Tarsem Singh. “When Kellan came in to read, I thought he was perfect. His physique and work ethic were fantastic. And I didn’t need to do any [physical] enhancements in postproduction, so he made my job easier.”

Hercules: The Legend Begins will hit theaters on Jan. 10.