In Cillian Murphy’s extreme physical transformation of Oppenheimer: how the actor used grueling and “unhealthy” methods to play the “almost emaciated” physicist who “never ate”
The stars of upcoming blockbuster Oppenheimer have revealed the “grueling” lengths Cillian Murphy went to become the “father of the atomic bomb” – saying the actor ate “an almond a day” to transform himself into the “gaunted physicist.
The Peaky Blinders star, 47, will star as J Robert Oppenheimer in the biopic directed by Christopher Nolan, due out Friday, which follows the scientist as he designs the nuclear bomb during World War II as part of the top-secret Manhattan project .
Cillian has previously detailed how far he went in an effort to portray the physicist on screen, losing weight to reflect his “almost emaciated” stature.
His co-star Emily Blunt spoke about Cillian’s drastic transformation, sharing how he survived on just an “almond a day” in his grueling diet.
In an interview with Additionaldescribed Emily — who plays his on-screen wife Kitty — the “monumental undertaking” of slimming down for the role.
Transformation: Cillian Murphy (left in 2017 and right in July 2023) underwent a drastic transformation to portray the ‘father of the atomic bomb’ J Robert Oppenheimer in the biopic
Drama: The Christopher Nolan-directed epic follows Oppenheimer (Cillian filmed last year) as he heads the lab that designs the atomic bomb during World War II
She said, “He had such a monumental business. And he could only eat one almond a day. He was so emaciated.’
Cillian Murphy spent five months transforming his body for Oppenheimer
Cillian warned that his transformation was not “healthy.”
Talking to the New York Timestold the star how he needed more than five months before filming to prepare for the role both physically and emotionally.
He confessed that he was “loved” by the physicality of preparing for the role, sharing how he wanted to lose weight to give Oppenheimer a “big eye” to show that he “never ate.”
He said, “I like 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 sizing; he was very slim, almost emaciated, lived on martinis and cigarettes.
“He had really bright eyes and I wanted to give him these big eyes, so we worked a lot on his silhouette and expression before we started.”
Extreme: Cillian (pictured in April) hasn’t shied away from describing the extreme heights he went to portray the physicist, while losing weight to reflect his ‘almost emaciated’ stature
Weight loss: His co-star Emily Blunt talked about Cillian’s transformation, sharing how he only ate an ‘almond a day’ (he’s pictured on the left on Peaky Blinders in 2021 and right in July 2023)
Drastic: Cillian (pictured in July 2023) also shared how he tested himself on how little he could eat while gearing up for the role, confessing that he ‘doesn’t advise’ the extreme diet
Real life: Cillian explained that Oppenheimer (pictured) “never ate” and lived on “martinis and cigarettes”
Cillian Murphy advises against extreme dieting after losing weight for the Oppenheimer movie
Cillian also said he was testing himself on how little he could eat, confessing that he “doesn’t advise” the extreme diet.
He told The protector: ‘You become a bit competitive with yourself and that is not healthy. I don’t recommend it.’
The actor said he wouldn’t reveal exactly how much weight he lost for the role, but talked about how the hectic pace of filming helped him stop worrying about food.
He slept for a few hours during filming, he said, adding, “I was running on crazy energy; I crossed a threshold where I didn’t have to worry 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.’
Cillian also shared how director Nolan gave the stars about six months to prepare before filming.
He told the Associated Press, “We had a lot of time to prepare, Chris always puts a lot of time into the prep, which I love, so we had about six months before we were actually shooting.
“You dive in, you immerse yourself in it.”
Emily Blunt plays Kitty, the wife of physicist Oppenheimer, while Florence Pugh plays Jean Tatlock, a psychiatrist, Communist Party member and close friend of J Robert Oppenheimer.
The film is an adaptation of the 2006 book American Prometheus: The Triumph And Tragedy Of J Robert Oppenheimer, by Kai Bird and Martin J Sherwin.
The book, which won the Pulitzer Prize, chronicles Oppenheimer’s personal life and his time as leader of the Manhattan Project in the early and mid-1940s.
Expect: Cillian takes on the role of Oppenheimer and critics have tipped the film to win big. He is pictured with Emily Blunt, who plays his on-screen wife Kitty
Cast: Florence Pugh plays Jean Tatlock, a psychiatrist, Communist Party member and close friend of Oppenheimer
The film has already been hailed as a contender to win multiple awards.
Journalists have taken to Twitter to share their glowing reviews of the film, with one critic describing how the film “slit my brain open” and “left me sobbing through the credits.”
Robbie Collin from The Telegraph wrote, “Am torn between being very coy and mysterious about Oppenheimer and just coming out and saying it’s a total knockout.”
Elsa Keslassy of Variety added: ‘A sign that French audiences loved #Oppenheimer is that they stopped in front of the Grand Rex theater long after the film ended to discuss it!’