Christian Bale is no stranger to shape-shifting for a role. He famously transformed himself from an underweight wisp for his role in The Mechanist into superhero shape for Batman Begins in a matter of months (thanks to Hollywood trainers and muscle memory, no doubt). For his latest transformation, he’s turned himself into an older man to play Dick Cheney in the upcoming Vice.
A poster child for modern Hollywood glamour, Charlize Theron gained weight and did away with every ounce of glamour in her body to play her gritty role in Monster (2003), for which she won an Oscar.
Having already used prosthetics to age herself for The Grand Budapest Hotel, Tilda Swinton wears prosthetics again and switches gender in the upcoming Suspiria. Or, at least, that’s what everyone assumes. The part is actually being credited to the name “Lutz Ebersdorf.”
Matt Damon ran 13 miles a day and ate only chicken breast to lose weight for his role in Courage Under Fire, which proved to be his first major breakthrough role as an actor before Good Will Hunting.
Mariah Carey, the portrait of pop diva glamour, allowed herself to go through a drastic make-under for her critically acclaimed role as a social worker in Precious.
Halle Berry wore prosthetics for her multiple roles in the Wachowski sisters’ 2012 film, Cloud Atlas. Here, she plays a 1930s English socialite.
Dramatic transformations are far more common in comedy (and, looking back, often problematically so), but Tom Cruise’s transformation into the power hungry agent Les Grossman in Tropic Thunder is still a standout in his long career 10 years later.
Already lithe, Natalie Portman lost weight and got herself into dancer shape in preparation for her Oscar-winning role as a psychologically tortured ballerina in Black Swan.
In the role that perhaps started all those jokes that all an actress needs to do to win an Oscar is “uglify” herself, Nicole Kidman wore a prosthetic nose to play the poet Virginia Woolf in The Hours. Sixteen years later, we think we can all agree that it was Kidman’s acting skills that won her the accolades, and not the nose.
Having been in beefcake shape just a few years before for Prince of Persia, Jake Gyllenhaal lost 20 pounds for his role as an unethical freelance photographer in Nightcrawler.
A decorated multi-sport child athlete (she once competed in the Junior Olympics), Hilary Swank still had to gain 20 pounds of muscle for her role in Million Dollar Baby (2004).
Once regarded as just a Hollywood beefcake, Matthew McConaughey lost 47 pounds for his role in Dallas Buyers Club and ultimately won an Oscar for the performance.
Everyone remembers that the album art for 50 Cent’s major label debut record, Get Rich or Die Tryin’, could have doubled as a Men’s Health cover, but the rapper dropped 50 pounds for his role in All Things Fall Apart.
Renée Zellweger gained weight, added padding, and even mastered a British accent for her role as a depressed everywoman in Bridget Jones’s Diary (in the sequels, she relied more on the padding rather than going through the full transformation again).
Tom Hanks lost major weight and grew his beard and hair out for his role as a man stuck on a deserted island in Cast Away.