'Wonka' director Paul King gained 50 pounds by scoffing the movie's specially-made sweets.

The moviemaker took charge of the musical prequel to 1971 film 'Willy Wonka and the Chocolate Factory' which stars Timothee Chalamet as the titular character - and he has revealed they brought in an expert chocolatier to make sweet treats for the film and he couldn't resist tasting them all.

He told PEOPLE: "We had this incredible chocolatier. She made these incredible concoctions, and we would taste them ... They tasted much better than they needed to, because obviously actors are good at pretending things, but the miracle was they tasted every bit as good as they looked ... I think I've [gained] about 50 pounds, but I hope I can lose it before [the movie] comes out."

King went on to add the extra chocolate on set didn't seem to affect the film's star, joking: "It's a miracle that Timmy remains so slim and handsome. I'm trying to fatten him up, but it's hard to do."

It comes after King revealed Chalamet didn't even have to audition for the role - because the director knew he was the perfect actor to take on the character of Willy Wonka.

He told Rolling Stone magazine: "It was a straight offer because he’s great, and he was the only person in my mind who could do it. But because he’s Timothee Chalamet and his life is so absurd, his high school musical performances are on YouTube and have hundreds of thousands of views. So I knew from stanning for Timmy Chalamet that he could sing and dance really well."

'Wonka' hits cinemas in December.