In fact, it was the second time in as many films he'd lost a significant amount of weight for a movie, something he said has made him "a little bit fatigued."
"I had to lose a lot of weight for Papillon. I didn't have to, but I thought it was important. Seeing as Michael [Noer] had made the decision that he was going to try to shoot the film as sequentially as possible, I thought it lent itself to a nice opportunity to lose some weight on camera through the journey of the film," Hunnam told the Boston Herald. "I did that twice in a row, which was unfortunate, 'cause I did that on The Lost City Of Z too, and not that it really shows an enormous amount on camera, but I actually lost 40 pounds through the course of shooting The Lost City Of Z and I think I did very close to losing 40 pounds again through the course of this film. So whatever is required."
Before Papillon and The Lost City of Z, Hunnam put on "a lot of weight" for the upcoming film Triple Frontier — only to lose it all afterward.
"The last film that I did, with the J. C. Chandor film that I did, I had to put on a lot of weight because I was playing a soldier and it was appropriate that I be a little bigger. Then, the last two films, both me and the directors decided that it would be better for me to have a smaller frame and so I immediately lost that weight again. I'm a little bit fatigued with the constant fluctuation of weight, but it's just part of the job," Hunnam explained.
In Papillon, Hunnam plays Henri "Papillon" Charriere, a Devil's Island prisoner and escapee in the 1920s French colony of Guiana who spends eight days in solitary confinement. Having premiered to $4.1 million worldwide, Papillon is playing in theaters now. Those who missed The Lost City of Z can find it on DVD and Blu-Ray.
Sons of Anarchy fans gearing up for the Mayans M.C. spinoff, which premieres Tuesday, Sept. 4 at 10 p.m. on FX, will not find Hunnam on their screens, despite the show being set in the same world as the hit FX original series.
"No, no… I had the deepest experience of my career coming out of that," the 38-year-old explained of Sons of Anarchy ending in 2014. "I had become that character, had become so deeply integrated into who I was, I literally didn't realize until the day we wrapped and we put him to rest and I felt I went through a period of two or three weeks of, like, real bereavement."
He explained that he thinks of Jax Teller as a "sacred" role, making it clear he won't be reviving him anytime soon.
"I have his cut [leather vest] and, you know, people have been to my house and asked if they could try it on and I [say] 'No one will ever put that cut on again' and 'We got to respect that dude. He's not with us anymore,'" Hunnam said. "So I would never bring him back from the dead for something like that… It was seven years of my life. He sort of became sacred to me."