"If you were any thinner, you wouldn't exist."
The most infamous of Bale's transformations, the one that qualifies as truly grotesque, was to play Trevor Reznik, an unstable, insomniac factory worker who loses his mind when he's fired after a workplace accident in this 2004 thriller. Nothing says commitment like Bale's 63-pound weight loss—a third of his body weight—that left his ribs protruding, his eyes sunken and his emotions dulled.
No fancy tricks here, other than starving himself with a diet of black coffee and an apple and one can of tuna a day, plus vitamins and mineral supplements.
"It just didn't enter my head that it could be done any other way, really," he told the BBC. "I just realized, 'Okay, I have to lose weight.' I just had no idea how much I would have to lose in order to get the look that I was searching for.
"I had a photograph of [country singer] Hank Williams when he was only 29, but he was looking like he was coming on 50, I guess just from abuse. It was a photograph of him getting released from jail just a few months before he died. He's shirtless and he looks a wreck, absolutely emaciated. So I stuck that on the front of the script to be kind of my image of what Trevor should be, and then just kept going and going and trying to reach that."
He ended up at 121 pounds, while the lowest healthy weight advised by a nutritionist was 145. (Also, writer Scott Kosar used his own height as a benchmark for proportional thinness and hadn't yet adjusted the target weight before Bale, who's about 6 inches taller, got the script—which described Trevor as "a walking skeleton"—and took that number as a challenge.)
"It's an amazing experience doing that," Bale recalled to The Guardian in 2018. "When you're so skinny that you can hardly walk up a flight of stairs...you're, like, this being of pure thought. It's like you've abandoned your body. That's the most Zen-like state I've ever been in my life. Two hours sleep, reading a book for 10 hours straight without stopping...unbelievable. You couldn't rile me up. No roller coaster of emotions."
Probably because he didn't have the energy to feel any emotions.
"As soon as you start putting the food back in your stomach, the roller coaster comes back," he added. After they shot the most skeletal scene, when Bale mock-preens in front of Jennifer Jason Leigh, he started gaining weight.