Matt Damon Says He Will No Longer Gain Weight for Movie Roles

Matt Damon says he is putting his health first and will no longer gain a lot of weight for movie roles.

The 55-year-old actor recently spoke with PEOPLE about preparing for Christopher Nolan's upcoming movie The Odyssey. Damon plays Odysseus, a Greek warrior who spends years trying to return home after the Trojan War.

To get ready for the role, Damon lost weight until he reached his high school weight of 167 pounds. He said he made the change in a healthy way.

"I didn't change it in an unhealthy way," Damon said. "If I had gone the other direction and gained weight, that would have been dangerous. It's not something I'll do anymore. I was willing to do it earlier in my life."

Instead of following a strict crash diet, Damon said he made healthy lifestyle changes. He focused on exercise, ate carefully, and removed gluten from his diet.

"You have to be very intentional about everything you're putting in your body," he said.

Earlier in his career, Damon gained about 30 pounds to play whistleblower Mark Whitacre in the 2009 film The Informant!. Looking back, he says he would not do that again.

Damon has also warned other actors about the risks of gaining weight for roles. His Oppenheimer co-star Josh Hartnett shared that Damon advised him not to gain 30 pounds for a part. By the time Damon gave the advice, Hartnett had already gained the weight.

Hartnett recalled Damon saying that it can be very difficult to lose the extra weight because the body often tries to return to its heavier size. Hartnett joked that the warning came too late.

Today, Damon prefers to use body prosthetics instead of changing his weight. He did this in the 2023 film Air, directed by his longtime friend Ben Affleck.

Affleck said the filmmakers used a body suit and camera techniques to make Damon appear heavier on screen. He wanted Damon to look more like an underdog rather than his usual action-hero image.

The Odyssey will be released in theaters on July 17.