David Harbour Opens Up About His Dramatic Weight Loss For Stranger Things 4

In an interview with British GQ, the 47-year-old actor revealed he lost a whopping 80 pounds between seasons 3 and 4 of the Netflix series, transforming his character's infamous dad bod for a slim, emaciated prisoner.

As viewers know, much of "Stranger Things 4" found Harbour's character, Sheriff Jim Hopper, trapped in a Russian prison camp. To appear as a prisoner -- on a prisoner diet -- Harbour dropped a ton of weight, telling British GQ that he achieved his transformation, which took eight months, by intermitting fasting and doing Pilates. However, the "Black Widow" star admitted that he doesn't plan on losing that much weight for a project again.

"I lost about 80 pounds from season three -- I was about 270 [then], and when we shot [season four] I was around 190," Harbour shared. "I don't think I'll ever do that again."

"I have this Santa Claus movie coming out for Universal in December ['Violent Night'] and I gained [it all back]," he added. "But now, yeah, never again. The prosthetics are too good."

Speaking of which, Harbour previously spoke about how "Stranger Things'" makeup designer Barrie Gower used prosthetics for the scenes when Hopper first arrived at the prison, AKA before his character would have lost weight.

"At the end of s3 I told those Duffer bros that we should shoot the flashbacks post 'death' cause I was going to lose the weight and there’d be continuity issues. But they hadn't been written yet," Harbour wrote in an Instagram post last month, above, sharing photos of the transformation. "Luckily, we had the miraculous @barriegower come in and give me the 'fuller hopper' face. I hate prosthetics, but Barry/team made it as painless as possible. The results speak for themselves."

Meanwhile, also during his wide-ranging interview with British GQ, Harbour revealed the moment he knew he was in love with his wife Lily Allen, whom he met on a dating app when he was in London filming "Black Widow."

While Harbour said Allen "claims to have fallen in love at first sight with me," he shared that he "remember[s] the exact moment."

"It was our third date," he told British GQ "I was just in this phase where I was like, 'I'm just going to be brutally honest about everything,' because why lie? And I told her something about my life, about my beliefs…"

"It would take a really extraordinary person to be accepting of the things that I said," he added. "And I remember thinking: Wow, that’s somebody I want to be around."

Harbour and Allen, 37, married in September 2020.