Cillian Murphy made the ultimate sacrifice for his art by ditching his vegetarian diet.

The Irish actor had been a dedicated vegetarian for 15 years, but started eating meat again to star as the charismatic but murderous crime boss Tommy Shelby in BBC show Peaky Blinders so he didn’t look like a “skinny Irish fella” onscreen.

The 40-year-old actor explained he made the switch back to eating meat upon the recommendation of the personal trainer tasked with helping him to bulk up for the first series of the crime drama back in 2013.

“I was vegetarian for about 15 years. But it was never a moral decision,” he explained to Mr Porter magazine. “It was more that I was worried about getting mad cow disease (an infectious disease in the brain of cattle).

“For the first series of Peaky Blinders, they were anxious that I shouldn’t look like a skinny Irish fella, and my trainer recommended meat,” shared the actor, who is currently on location in Liverpool, England, filming the fourth series of the critically acclaimed show.

Cillian’s physique is somewhat concealed under the well-cut 1920s attire he sports on the BBC program. The Peaky Blinders style has some very famous fans in David Beckham and his son Brooklyn, but when it comes to his own style, Cillian isn’t very adventurous and likes to keep it simple.

“You can’t go wrong with navy. My taste is very much: a good pair of jeans, a good jacket, a good pair of shoes. Well-made things that fit. I’m not adventurous,” the Free Fire star admitted.

While he had no qualms about bulking up for the period drama, Cillian admits he has no desire to do so to star as a superhero like Batman.

“I don’t think I’m the right physical specimen for Batman… playing the square-jawed hero or the nefarious villain doesn’t really interest me. Humanity falls somewhere in the middle,” he insisted.