Matt Damon recently revealed his impressive physical transformation for his role in the upcoming film, The Odyssey. During an appearance on the “New Heights” podcast on January 7, the 55-year-old actor discussed the significant weight loss he underwent to embody the legendary hero Odysseus.

Damon explained that director Christopher Nolan envisioned a portrayal of Odysseus that was both “lean but strong,” prompting the actor to embark on a rigorous regimen. “I was in really good shape. I lost a lot of weight,” Damon shared, attributing part of his success to eliminating gluten from his diet.

The commitment to his role saw Damon drop from his usual weight range of 185 to 200 pounds down to a striking 167 pounds for the film. “I haven’t been that light since high school,” the Oscar winner remarked, reflecting on the intense training and strict dietary discipline required to achieve such a transformation. “I have a trainer, and they’re like, ‘What are we doing?’ It’s really about having a clear goal and sticking to it.”

In the world of film, actors often go to extraordinary lengths to authentically portray their characters. Matt Damon joins a long list of Hollywood stars, including Matthew McConaughey, Anne Hathaway, Renee Zellweger, and Christian Bale, who have notably altered their physiques for the sake of their craft.

Some stars go to great lengths to get into character. Matthew McConaughey, Anne Hathaway, Renee Zellweger, and Christian Bale are just a few of the many celebrities who’ve lost or gained significant amounts of weight for movies

Damon considers his training to be “a part of [his] day” and job.

“You get really routinized about it and build your day around all that stuff,” he said. “That’s kind of the physical side of getting ready.”

In addition to spending time in the gym, Damon also adopted a gluten-free nutritional plan.

“I’m gluten-free everything. I found a gluten-free beer,” he said. “It’s been so long since I’ve had gluten, I can’t tell if it’s good or not, so that’s a good sign.”

The Odyssey is adapted from Homer’s poem of the same name about Odysseus’ 10-year journey home from the Trojan War. The film also stars Anne Hathaway, Tom Holland, Robert Pattinson, Lupita Nyong’o, Zendaya, Charlize Theron, Mia Goth and more.

“I’m a fan [of Christopher Nolan]. I just love the movies that he makes and also just the way he insists on shooting them,” Damon teased of the film production. “This one was 100 percent on IMAX. It was the first movie that was ever done all on IMAX, like, IMAX cameras are really loud. It sounds like a blender [or] a Cuisinart in your face.”

Shocking, indeed! Some celebs seek out extreme methods to shed pounds, while others transform with the aid of healthier methods. From Rosie O’Donnell’s and Jordin Sparks’ respective 50 pound weight losses to Biggest Loser winner Rachel Frederickson’s whopping 155 lighter frame, see before and after pictures of celebrities’ weight loss transformations.

Because of the noisy camera, the actors weren’t able to film dialogue scenes like normal.

“They built this giant thing around the IMAX for those dialogue scenes and a system of mirrors so your eyeline would be close to the camera and you could talk to the other actor,” Damon said. “The amount of work that went into figuring out how to do ‘cause he wanted to do it 100 percent IMAX, and he did it. It’s, like, a really ambitious kind of idea that he has on the technical side.”

Damon continued, “Then, there were locations that we went … where we would get there and I’d just start laughing. I’d be, like, ‘Nobody has any business shooting here, but of course he wants to shoot here.’”

Damon further praised Nolan’s “great crew” for putting together the ambitious epic.

“His crew is so badass and everybody just maxed out on that movie and we made all of our days. We actually finished ahead of schedule,” he said. “It was an awesome experience, [but] it was just an awesome experience. I haven’t seen it yet.”