Joker Star Joaquin Phoenix Starved Himself to Lose Weight for Arthur Fleck Role

Joaquin Phoenix ate "an apple a day" to slim down for Joker, where he plays the nearly skin-and-bones Arthur Fleck. According to director Todd Phillips, Phoenix declined the help of a nutritionist and other experts to lose some 52 pounds as Phillips and co-writer Scott Silver envisioned a scrawny Arthur-slash-Joker. The weight loss ultimately proved so dramatic Phoenix's co-star Glenn Fleshler, who plays Arthur's co-worker Randall, almost didn't recognize Phoenix during a table read. As Phoenix explained at the Venice Film Festival earlier this year, such drastic weight loss "affects your psychology. You start to go mad when you lose that amount of weight in that amount of time."

"We talked a lot about, 'How skinny should Arthur be? How far do we want to go?'" Phillips says in the Joker: Vision & Fury special feature included on the film's home release. "And I kept saying to him, 'When are you gonna start losing weight? At what point do you start this?' Because it was already like June, and he hadn't started, and we started shooting in September. And he's like 180 pounds. He wasn't fat, but we're talking getting to 125 pounds."

Phillips continues, "And he goes, 'I got it, I got it.' I go, 'We can hire a guy, I've got this woman who's a nutritionist, you might want to [talk to her].' 'No no, that's not how I do it.' I go, 'How do you do it?' He goes, 'I just stop eating and I starve myself.' He just ate an apple a day for the whole summer."

For Fleshler, Phoenix's eventual physical transformation was a surprise. "When I laid eyes on him at a table read, he'd lost 50 pounds. He was like a shell of himself," he says. "He was fully immersing himself in the role."

That immersion also meant engaging in lengthy conversations with Phillips about the psychology of the mentally unwell Arthur, which Phillips and Phoenix largely wanted to leave ambiguous.

"We talked a lot about who would he be, and why is he like this, and what is his thing, and where does that laugh come from, and why does he wear makeup or not, [and so on]. And we really just started reading a lot about narcissism, and ego, and things that we think that are kind of baked into our version of Joker," says Phillips, who adds this Joker is "a narcissist, but he's an egoless narcissist in our mind."

"The ego is Arthur, the ego is the thing that's trying to control this wild force that is Joker. But Joker is pure id," Phillips explains. "So we just thought, 'What happens when you go through your life wearing a mask?' Which a lot of people do, you're wearing a mask and you're pretending to be a certain way. And Arthur is very kind of controlled, but there are these glimpses of who he is underneath. And what happens when you take the mask off, which is kind of a weird flip, because actually Joker wears a mask — or makeup — but the idea is, 'What happens when you stop living that life, and live as the shadow?' Then you just make the movie and you forget all that, and you just make the film, and you hope it makes sense on some level."

Joker is available to own on 4K Ultra HD and Blu-ray January 7. Follow the author @CameronBonomolo on Twitter.