Joaquin Phoenix on Sunday night won a Golden Globe for best actor in a motion picture drama for his role as the troubled Arthur Fleck in Joker.

Other than his outstanding performance in the psychological thriller film, Phoenix lost an incredible amount of weight. To play the thin comedian turned maniac clown, Joaquin Phoenix shed over 50 pounds.

According to the Joker’s director and co-screenwriter Todd Phillips, Phoenix only started losing weight just three months before the shooting of the film began.

“It was already like June and he hadn’t started [losing weight] and we start shooting in September. And he’s like, 180 pounds. He wasn’t fat but we’re talking about getting to 125 pounds,” Phillips said.

Phillips was worried for Pheonix and proposed hiring an expert to help with weight loss but the 45 years old actor assured him that he could handle it himself.

“And he goes ‘I got it, I got it.’ I go ‘You know we can hire a guy. I got this thing, this woman who’s a nutritionist, you might wanna…’ ‘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.”

Phoenix later admitted to Access Hollywood that his weight loss diet was included more than just an apple and that he worked closely with a medical professional to lose weight safely.

“It wasn’t an apple a day. No, you’ve also got lettuce and steamed green beans,” Phoenix said. “It’s something I’ve done before and you work with a doctor regimented and overseen and safe.”

During his appearance on ABC’s “Jimmy Kimmel Live” show October last year, Phoenix confessed that it was quite exhausting and he couldn’t socialize with anyone because that would likely involve eating and drinking.

“In the beginning, you’re exhausted,” Phoenix said. “You look at a flight of stairs and it takes like 30 seconds. You have to talk yourself into it and say, ‘I can do this, I know I can do this.'”

Earlier in September, Phoenix spoke about his physical transformation in an interview with the Associated Press:

“I think the interesting thing for me is what I had expected and anticipated with the weight loss was these feelings of dissatisfaction, hunger, a certain kind of vulnerability and a weakness. But what I didn’t anticipate was this feeling of kind of fluidity that I felt physically. I felt like I could move my body in ways that I hadn’t been able to before. And I think that really lent itself to some of the physical movement that started to emerge as an important part of the character.”

It is not uncommon for actors to go through extreme measures to fit the character they are playing. Below are some Hollywood actors that have gone through such extreme physical transformation:

Christian Bale in The Machinist

For his role in The Machinist, Bale drastically dropped down to 121 pounds — losing 63 pounds in four months — before doctors told him to stop because they thought he was near death.

Charlize Theron in Monster

To convincingly play the serial killer Aileen Wuornos in Monster — a role that won her an Oscar — Theron packed on 30 additional pounds.

Jake Gyllenhaal in Southpaw

Gyllenhaal gained 15lbs of muscle to play a middleweight boxer in the movie Southpaw by working out six hours a day for six months, including at the Las Vegas gym of Floyd Mayweather, the champion boxer.

Matt Damon in Courage Under Fire

Damon lost 40 pounds to play a drug-addicted veteran in Courage Under Fire, and was placed on medical supervision for seven months after filming as a result of such a dramatic loss.

50 Cent in Things Fall Apart

For his role as a football player who succumbs to cancer in Things Fall Apart, the 50 Cent went from 214 pounds down to 160 pounds by running for three hours a day and existing on a purely liquid diet.