Jared Leto felt compelled to temporarily pause filming Tron: Ares because of one dude.
Indeed, the Thirty Seconds to Mars singer was just bowled over by the fact that his costar was Jeff Bridges.
"I remember the first day I worked with Jeff, I had to yell, 'Cut!'" Jared recalled to E! News' Will Marfuggi in a joint interview with Jeff at the Los Angeles premiere of Tron: Ares Oct. 6, "and they came over, they were like, 'What's wrong?' and I was like, 'I couldn't stop smiling.' Because I'm working with him for the first time, and I'm in the costume, the sets look incredible.'"
And that enthusiasm went both ways. Jeff—who reprised his role of Kevin Flynn in Tron: Ares—admitted that he and Jared the two "hit it off right from the top."
In fact, when the Big Lebowski star, 75, first met Jared, he immediately made a point to emphasize acknowledge that 53-year-old—who played the titular advanced artificial intelligence program sent into the physical world—utilizes method acting on set.
"I asked him when I first met him, 'Hey man, this is the first time we're working together. I understand you like to be called by your character's name. Do you mind if I call you 'Ar'?" Jeff recalled. "He laughed and said, 'You can call me that."
Although, Jared, admitted, at the time he was quick to respond, "You can call me whatever the hell you want, Jeff."
But that’s not the only way the duo bonded on the set of the third installment of the Tron franchise, which releases in theaters Oct. 10.
"We did a whole thing of me giving you the original Tron helmet," Jeff recalled to Jared in a video released by Walt Disney Pictures, "a passing on the torch kind of thing."
While the sci-fi film saw both Jeff and Jared looking remarkably different from their offscreen personas, they aren’t the only stars who’ve made major changes for a role. Keep reading for more…
Channing Tatum
The Magic Mike star's weight has fluctuated over the years, especially in 2024, as he got into character for two back-to-back movie roles.
He said on Instagram in March 2025 that he currently weighed 205 pounds—up from the 172 pounds he weighed for Roofman (pictured, right). Months before beginning production on that 2024 film, he shot the movie Josephine (pictured, left) and weighed 235 pounds for his role.
Timothée Chalamet
For his Oscar-nominated role as musician Bob Dylan in A Complete Unknown, the Dune actor learned how to sing and play guitar.
"I also put on 20 pounds," he said during a January 2025 episode NPR’s All Things Considered podcast, "because, believe it or not, I was thinner than the guy.”
Cillian Murphy
To play scientist J. Robert Oppenheimer in Christopher Nolan's Oppenheimer, the Irish actor "had to lose quite a bit of weight," he shared. "He was very slim, almost emaciated, existed on martinis and cigarettes." His diet? According to costar Emily Blunt, "He had such a monumental undertaking.And he could only eat, like, an almond every day."
Joaquin Phoenix
For his Joker role, the Oscar winner opened up about his 52-pound weight loss, telling the Associated Press, "Once you reach the target weight, everything changes. Like so much of what's difficult is waking up every day and being obsessed over like 0.3 pounds. Right? And you really develop like a disorder."
J.K. Simmons
The Spider-Man alum shocked fans when he debuted his bulging biceps, which were displayed in Justice League.
Jake Gyllenhaal
"I'd say my mother was worried," he previously told E! News after losing 30 pounds for Nightcrawler. "I would say she just wanted me to be careful. But she also knew and knows how seriously I take what I do and she respects that."
Orlando Bloom
The Pirates of the Caribbean alum detailed the physical and emotional toll of losing 52 pounds for his boxing movie The Cut.
“I was exhausted mentally, physically. I was hangry,” he said on This Morning. “I was a horrible person to be around. The paranoia, the intrusive thoughts.”
“I wouldn’t recommend doing it at home, by the way,” he continued. “It was definitely not something to take lightly.”
Michael B. Jordan
The Black Panther star gained nearly 30 pounds of muscle to transform into a rookie-turned-professional boxer in Creed.
Jared Leto
The actor and musician nabbed an Oscar for his riveting role in The Dallas Buyers Club. He lost 40 pounds for the role.
Chris Messina
The Mindy Project alum had to gain 40 pounds for his role in Live by Night.
Renée Zellweger
The Bridget Jones's Diary actress gained weight to portray the lovable character in the franchise's first and second films.
Matthew McConaughey
The Magic Mike hunk dropped 30 pounds to star in The Dallas Buyer's Club—which centered on the real-life story about a man dying from AIDS in the 1980s who treated himself with alternative remedies he smuggled into the United States from Mexico.
Rooney Mara
The actress looked lean and strong for her starring role in The Girl With the Dragon Tattoo.
Anne Hathaway
The Les Misérables star took home an Oscar for her role in the musical.
Christian Bale
He's no stranger to morphing for movie roles. In 2004, he lost more than 60 pounds for his role in The Machinist, and he did it again for the film The Fighter, opposite Mark Wahlberg. He also gained 40 pounds for American Hustle—and lost 70 pounds for Ford v Ferrari.
Jake Gyllenhaal (Again)
The actor looked more like a god than a prince for his role in 2010's Prince of Persia. Gyllenhaal said he studied Parkour, the French art of street running, in order to bulk up for the film.
Tom Hanks
"All it is is time and discipline," the Oscar winner told Time magazine of his role in 2000's Cast Away, for which he lost over 50 pounds to play a man stranded on an uninhabited island.
50 Cent
The ripped rapper shocked fans with a photo of himself looking slender. He reportedly went from 214 to 160 pounds in just nine weeks to play a football player diagnosed with cancer in Things Fall Apart.
Robert De Niro
Shaping up for movie roles is nothing new. The legendary actor earned an Oscar nom for his role as terrifying tattooed rapist Max Cady in the 1991 thriller Cape Fear.
Christian Bale (Again)
In order to portray former Vice President Dick Cheney in the 2018 biopic Vice, the star sported a fuller figure.