Actor Cillian Murphy underwent a significant physical change to portray scientist J Robert Oppenheimer in Christopher Nolan's upcoming film, Oppenheimer. His co-star Emily Blunt, who plays his wife, recently shared details about his shocking diet during filming.

Blunt disclosed in an interview with Extra that Murphy followed a highly restrictive diet for the role, subsisting on only an almond a day. She described his appearance as "emaciated" due to the monumental task he took on for the character.

During another interview with IndieWire, Murphy advised against extreme weight loss for roles, stating, "I don't advise it." However, he didn't specify how much weight he lost, preferring not to emphasize that aspect.

Matt Damon, who portrays Lt. Gen. Leslie Groves, praised Murphy's dedication, considering the immense workload and attention to detail required by Nolan. Murphy revealed that he was functioning on "crazy energy" during filming, fully immersing himself in the role. The character of Oppenheimer, as portrayed by Murphy, was depicted as someone who never ate, and his transformation aimed to resemble the real-life Oppenheimer, who survived on cigarettes and pipes.