Will Poulter whisks a lot faster now.
After all, before The Bear star was making decadent desserts in the FX series—for which he earned an Outstanding Guest Actor in A Comedy Series nomination at the 2024 Emmys Sept. 15—he was stepping into the Marvel Cinematic Universe for Guardians of The Galaxy: Vol 3. That, of course, required a major fitness journey to transform into his super-human character.
And it came from the help of his personal trainer because to achieve the look of the shining Adam Warlock, he had to emulate perfection—or as close as he could.
"Will wanted to look as close to a Greek God as possible," Dr. Benjamin Carraway told GQ in December. "I had medical doctors and psychiatrists helping me—I brought in a team of consultants. As a perfectionist, the consequences of him injuring himself or burning out with the training would have caused him a lot of psychological issues."
But Will—who earned one of The Bear's 23 nominations at the 2024 Emmys— was also aware that the process of his fitness transformation was an immense privilege.
"I had so much of the hard work done for me," he explained to Variety in July 2022. "It was actually my job just to kind of train and eat, so I've got no complaints."
And the 31-year-old was ready for the challenge because, as he told The Independent earlier that year, Warlock was "genetically engineered by scientists to be the perfect being."
"The most important thing is that your mental and physical health has to be number one," he explained. "The aesthetic goals have to be secondary. Otherwise, you end up promoting something that is unhealthy and unrealistic if you don't have the financial backing of a studio paying for your meals and training."
As for what he did to develop his buff physique?
"It's been a lot of gym work and a very, very specific diet," he revealed. "Quantities of food you wouldn't necessarily want to ingest. And other times not enough food. I've gone through a series of different diets over the last few months."
"I've gone through periods of looking at food and feeling like I can't face it," the We're the Millers actor continued. "Then you blink and the next minute you're ready to eat furniture because you're so hungry."
And while Will knows he looked good after bulking up for the 2023 film, and has even kept the muscular physique for his role as pasty chef Luca in The Bear, it's incredibly unrealistic in day to day life. He noted, "I wouldn't recommend anyone do what I did to get ready for that job."
Keep reading to see other celebs who've gained or lost weight for their roles.
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.