See Jessica Simpson’s Plastic Surgery Prosthetics in All’s Fair

Christian Bale, American Hustle & Vice

The British actor packed on more than 40 pounds for his Oscar-nominated performance as a beer-bellied con artist in 2013's American Hustle. He put on the same amount to play former U.S. Vice President Dick Cheney in the 2018 movie Vice, which also earned him an Oscar nomination.

For his 2019 movie Ford v Ferrari, Bale dropped dropped 70 pounds to play slender race car driver Ken Miles. And it wasn't his first time losing weight for a role, having also lost about 30 pounds while filming the 2011 film The Fighter.

Glenn Close, Hillbilly Elegy

Sebastian Stan, The Apprentice

For his role as Donald Trump, not only did the actor work with the same hairstylist and makeup artists who transformed him into Tommy Lee for 2022's Pam & Tommy, but he also packed on the pounds to fill out the reality star-turned-president's frame.

Stan said he gained around 15 pounds by eating instant ramen mixed with soy sauce—a dish recommended by his nutritionist to look bloated in the face—and drinking soda.

Andra Day, The United States vs Billie Holiday

Cillian Murphy, Oppenheimer

Was eating, as his onscreen wife Emily Blunt joked "like, an almond every day," a bit nutty? Sure. But the Irish star really wanted to nail atomic bomb scientist J. Robert Oppenheimer's appearance.

"Oppenheimer had a very distinct physicality and silhouette, which I wanted to get right," he explained to The New York Times. "I had to lose quite a bit of weight, and we worked with the costume and tailoring; he was very slim, almost emaciated, existed on martinis and cigarettes."

Joaquin Phoenix, The Joker

The actress, who famously gained a reported 17 pounds to play the title role in Bridget Jones's Diary, did not have to change her physique to transform into Judy Garland for the 2019 film Judy, for which she won her first Oscar. You can thank the makeup and costume department for her transformation.

"Renée was extremely emotionally and artistically involved in Judy, the movie's costume designer, Jany Temime, who also worked on the Harry Potter films, told Vulture. "It was her film. I think she really got into Judy's skin."

Zellweger told the outlet, "Jany fit the costumes to Judy's posture. So the dresses didn't fit me unless I stood like I was supposed to stand. The zipper wouldn't go up."

The late actor received a posthumous Oscar in 2008 for his chilling and mesmerizing performance as The Joker in the second film in Christopher Nolan's Batman trilogy. His look as the iconic villain differed greatly from those previously seen on past actors onscreen.

"What would it be if this guy slept in his makeup, this psychopath?" makeup artist John Caglione Jr. told IGN. "If he didn't spruce up his makeup for two or three weeks? He never changes his clothes It's those kinds of organic details that really helped."

He continued, "You think of a clown's makeup and for the most part, they're pretty detailed with sharp lines. But this had to be the opposite of that."

Hilary Swank, Boys Don't Cry & Million Dollar Baby

Ever the chameleon, the 2014 Best Supporting Actor winner prepared to play a HIV-positive transgender woman by losing 40 pounds and only staying in character on set. 

"I had done similar things with weight, but this was different," Leto told E! News in 2013. "I think the role demanded that commitment…It was about how does that effect how I walk, how I talked, who I am, how I feel. You know, you feel very fragile and delicate and unsafe."