Hayden Christensen gained 30 pounds to play Darth Vader in 'Obi-Wan Kenobi'

He told Fatherly: "I think that process (of putting on weight) was very important for me. I needed to become that character again, physically. I just consumed as many calories as possible. I put on 25 or 30 pounds to fill out that (Darth Vader) suit."

The 41-year-old actor explained it took nine months for him to bulk up and he tried to maintain his new physique after filming on the 'Star Wars' show wrapped, but he ended up going to back to his old ways.

Hayden added: "I try to avoid the dad bod thing. And I was trying to maintain that Vader body after we finished. But, honestly, I pretty much just went back to my old diet. I kind of deflated after that."

Hayden's co-star Ewan recently opened up about what it was like facing Darth Vader onset and admitted it was a terrifying experience.

During an appearance on 'The Tonight Show Starring Jimmy Fallon', Ewan explained: "It was frightening to see him again though. I hadn't acted with Darth Vader. "And I've been acting a long time. I think I've done a lot of stuff. But the first take with Darth Vader scared the s*** out of me."

When asked about seeing Hayden in the black suit for the first time, Ewan added: "They went, 'Action!' And I'm walking down and I hear something, I turn around and f*** Darth Vader is coming at me. I swear to god, I just about s*** my pants, really."