Sam Heughan became a meat eater after Superman Returns audition

Sam Heughan became a meat eater after being told to "eat more protein" for his 'Superman Returns' audition.

The 'Outlander' star, 41, failed his audition for the 2006 flick - with the titular superhero role ultimately going to Brandon Routh - but after being told he needed to bulk up for the part and "eat more protein" by his trainer, he found he had a lot more energy from ditching his "vegetarian-pescatarian" diet.

Speaking to Variety, Sam said: “I grew up a pescatarian or sort of vegetarian-pescatarian.

“I didn’t start eating meat until I came to America when I was 24. It was all these delicious burgers and food.”

He recalled: “I had a trainer and he was like, ‘You need to get bigger. You need to be able to fill out the cape.'

“I remember the first time I had chicken or something and just suddenly, I was like, ‘Oh my God, I have all this energy. And I don’t feel hungry all the time.'"

Meanwhile, Sam admitted that while he is excited to see 'The Batman', starring Robert Pattinson as the Caped Crusader, he is not a fan of some of the other superhero flicks.

He explained: “I think the other superhero movies kind of lost their way a bit.

"They’ve become, I think, a little too obese in a way, but anything character-based — I mean, Batman’s a great one because he’s not a superhero.

"He’s just an interesting character. Something with a good backstory.”