Josh Hartnett Shared Matt Damon’s Very ‘Unhelpful’ Advice On The ‘Oppenheimer’ Set

Actors are known to change up their look for new roles, and some of them do it more intensely than others. You can get jacked up or get a perm or even CGI genitals, if that is what the movie requires.

For Oppenheimer, Josh Hartnett admitted that he gained 30 pounds for the role, which is not unheard of in Hollywood. But his co-star Matt Damon seemed to give him a hard time about it. “He gave me a lot of good advice. One in particular — one thing that was just so unhelpful: he told me not to gain the weight I’d already gained for the role,” Hartnett told Jimmy Fallon this week on The Tonight Show.

For his role of Ernest in Chris Nolan’s 2023 blockbuster, Hartnett put on some weight. “I gained about 30 pounds for the role, and [Damon] was like, ‘You’re never gonna get that off again, man.’” He said. Apparently, Damon has a strict “don’t gain weight over 40” rule for himself when it comes to choosing his movie roles.

Hartnett then explained Damon’s point of view. “He’s like, ‘You’re gonna spend the rest of your life trying to get that weight off and it’s never gonna come off because your body’s gonna want to get that weight back on. You’re just gonna keep growing back out to that size, and you’re going to try and get it off, but it’s just gonna go back,’” he recalled. “And he kept telling me, like, over the course of the production.” Statistically, this is what happens when most people diet, so in a way, he’s right, and you should never push your body to do something it doesn’t want to do. On the other hand, haven’t we learned not to trust everything that Matt Damon says?

Hartnett took the advice like a champ. “I was like, ‘Thanks, Matt. Thanks for telling me this now. I’ve already gained it.’” And he looks GREAT! Take that, Matt!! Coincidentally, Damon was also a guest on The Tonight Show last night, so they must have patched things up.

TRAP is in theaters on August 2nd. Check out the full interview above.

(Via EW)