Cillian Murphy looks unrecognizable after dramatic weight loss: ‘I don’t advise it’

The Oppenheimer star ate ‘an almond every day’ according to his co-star

Cillian Murphy is winning rave reviews for his leading role in Christopher Nolan’s latest film, Oppenheimer – but his starring turn didn’t come without some sacrifice.

The 47-year-old underwent a dramatic transformation and lost so much weight for the role, his co-star, Emily Blunt, said he looked “emaciated” after going to extreme lengths to play American theoretical physicist, J. Robert Oppenheimer, the “father of the atomic bomb”.

“He had such a monumental undertaking. And he could only eat, like, an almond every day,” Emily – who plays Cillian’s on-screen wife, biologist Kitty Oppenheimer – said in a recent interview with Extra, adding: “He was so emaciated.”

During a separate interview alongside Matt Damon – who portrays Leslie Groves, the director of the Manhattan Project – the duo admitted that Cillian would refrain from joining the cast for meals because of his strict diet.

“We invited Cillian to dinner every night, and he never went. He was losing so much weight for the part that he just didn’t eat dinner, ever,” Matt told Entertainment Tonight, with Emily adding that Cillian survived on “one almond most nights or a little slice of apple”.

Cillian has also been open about the “overwhelming” lengths he went to in order to fully portray Oppenheimer, who he said lived on cigarettes and alcohol. “I love acting with my body, and Oppenheimer had a very distinct physicality and silhouette, which I wanted to get right,” he told the New York Times in May.

“I had to lose quite a bit of weight, and we worked with the costume and tailoring; he was very slim, almost emaciated, existed on martinis and cigarettes,” he added.

Despite his unhealthy approach to getting into character, the Peaky Blinders star admitted that the role of Oppenheimer was so demanding, he didn’t have time to think about his lack of food. “It’s like you’re on this [expletive] train that’s just bombing. It’s bang, bang, bang, bang. You sleep for a few hours, get up, bang it again,” he told The Guardian.

“I was running on crazy energy; I went over a threshold to where I was not worrying about food or anything…But it was good because the character was like that. He never ate.”

Cillian doesn’t advise anyone to follow his drastic weight loss methods and has refused to say exactly how much weight he lost for the role. “I don’t want it to be, ‘Cillian lost x weight for the part,’” he explained to the outlet.

He added: “You become competitive with yourself a little bit, which is not healthy. I don’t advise it.”

Oppenheimer, which will hit theaters on Friday, is based on the Pulitzer Prize-winning biography American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer, authored by Kai Bird and Martin J. Sherwin over a period of twenty-five years, which was released in 2005.

It details the life of Oppenheimer (1904-1967), his efforts to build the atomic bomb during World War II, and his inner turmoil as he faced “the moral consequences of scientific progress”.