Written by Finlay Mead

Oppenheimer’s leading man, Cillian Murphy, has been exposed by a co-star for his dangerously minimal diet during filming for the upcoming Christopher Nolan blockbuster.

Former Peaky Blinders star Cillian Murphy has been outed by co-star Emily Blunt as having an absolutely crazy — verging on life-threatening — diet during filming for Oppenheimer, which is set to release in Australia in only a matter of days. Described as ‘an experience‘ rather than a run-of-the-mill movie, the film is set to make waves across the industry, despite the walkouts amid the ongoing SAG-AFTRA strike which have put something of a dent in the last-minute publicity for the film.

Murphy underwent an extreme physical transformation in order to better embody the role of J Robert Oppenheimer, the reluctant father of the atomic bomb. Resorting to an alarming diet that left him “so emaciated” — as described by Blunt, who plays his on-screen wife — his industry-renowned dedication to authenticity meant that in an attempt to get Oppenheimer’s distinct physicality and silhouette absolutely spot-on, he adopted a pretty intense approach towards his diet and physique.

WATCH: Oppenheimer’s trailer is the bomb… pun very much intended.

As reported by The Evening Standard, the 40-year-old actress revealed that during filming, Murphy only allowed himself to eat one strange and minuscule thing — an “almond a day” — in order to achieve the desired look for his character. In an interview with The New York Times in May, Murphy opened up about his intense preparation for the role, saying this:

“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, existed on martinis and cigarettes.”

Cillian Murphy

While the actor has expressed his desire not to have the media focus solely on his weight loss — telling The Guardian earlier this month that he doesn’t want it to be, “‘Cillian lost X weight for the part’” — he also made it clear that his extreme diet should absolutely not be taken as a green light for members of the public to adopt the same kind of nutritional routine: “You become competitive with yourself a little bit, which is not healthy. I don’t advise it”.

We couldn’t agree more strongly with this. Having spoken to top nutritionists about the dangers of intermittent fasting, the importance of a high-protein diet for keeping your mental health buoyed up, and many of the more extreme weight-loss techniques out there, it should be pretty obvious that consuming so few calories each day is an incredibly risky idea, no matter how good it might make you look on-screen.

Despite the challenges of his demanding transformation, Murphy credited the fast-paced filming process for helping him achieve the look he envisioned for the pioneering controversial scientist:

“It’s like you’re on this f***ing train that’s just bombing. It’s bang, bang, bang, bang. You sleep for a few hours, get up, bang it again. 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…something. But it was good because the character was like that. He never ate.”

Cillian Murphy

Set to release later this week, Oppenheimer features an impressive ensemble cast, including Matt Damon, Florence Pugh, Robert Downey Jr., Rami Malek, and of course, Cillian Murphy alongside Emily Blunt.