How Much Weight Did Cillian Murphy Lose For Oppenheimer?

Christopher Nolan’s biographical film, ‘Oppenheimer’ takes the audience into the mind of the man who came to be known as “the father of the atomic bomb.” It focuses on J. Robert Oppenheimer’s life, from his demanding work on the Manhattan Project to his tumultuous romantic relationship with Jean Tatlock. While dealing with the upheavals in his personal life, Oppenheimer also has to make peace by creating something that has the power to destroy the world.

All of this is bound to take a toll on a person, and with the passing of each event, we see Oppenheimer becoming physically frail. Actor Cillian Murphy brings the genius scientist alive on the screen, not just through his impeccable acting but also through his physical appearance. If you are wondering about Murphy’s weight transformation in the movie, here’s what you need to know.

Cillian Murphy’s Weight Loss

Robert Oppenheimer is said to have been a frugal eater throughout his life. However, the two years he devoted to working on the Manhattan Project are said to have been incredibly daunting for his physical and mental health. According to ‘American Prometheus,’ the book on which Christopher Nolan’s movie is based, Oppenheimer was reduced to being “skin and bones,” with his weight dropping to 115 pounds. Reportedly, “his energy level never flagged, but he seemed to be literally disappearing little by little, day after day.”

When Cillian Murphy was hired to play Oppenheimer, the actor knew that bringing that physicality to the role was essential to doing justice to the film. Talking about Oppenheimer’s appearance and how the actor was inspired to morph into a similar form, Murphy said: “I love acting with my body, and Oppenheimer had a very distinct physicality and silhouette, which I wanted to get right. I had to lose quite a bit of weight, and we worked with the costume and tailoring; he was very slim, almost emaciated, and existed on martinis and cigarettes. He had these really bright eyes, and I wanted to give him this wide-eyed look, so we worked on his silhouette and expressions a lot before starting.”

Murphy was going for the silhouette “with the porkpie hat and the pipe” when he decided to start eating lesser and slowly lose weight. He started testing himself about how little he could eat and confessed that at one point, he started to get competitive about it with himself, which he called not healthy. He refused to mention how much weight he lost for the part because he doesn’t want to be a part of the “Cillian lost x weight” conversation. He also doesn’t advise taking the route he did for weight loss.

The role of Oppenheimer was so mentally and emotionally demanding that the actor started to forget eating and sleeping. The filming schedule was so packed that he got a few hours of sleep before jumping into the next scene. “I was running on crazy energy; I went over a threshold to where I was not worrying about food or anything. I was so in it, a state of hyper… hyper something. But it was good because the character was like that. He never ate,” the ‘Peaky Blinders’ actor said.

Talking about the real-life Oppenheimer’s eating habits, Murphy said: “Cigarettes and pipes. He would alternate between the two. That’s what did for him in the end.” The actor confessed that he has smoked so many cigarettes for ‘Oppenheimer’ and ‘Peaky Blinders,’ that he doesn’t want his next character to be a smoker. According to his co-star, Emily Blunt, Murphy got “emaciated” and only ate almonds. While this could comment could have been made in jest, she agreed with Matt Damon, who revealed that Murphy never went on a dinner with the cast during the filming period.

With the filming wrapped, Murphy went back to eating properly and had recovered a lot of weight by the time The Guardian interviewed him about ‘Oppenheimer.’ With all the hard work he put into the role, Murphy said he was happy with how the film turned out, calling it “provocative and powerful” and “an extraordinary piece of work.”

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