Zac Efron has revealed the lengths he had to go to in order to get a ripped physique for the 2017 movie Baywatch, declaring it "stupid" and "just not real".

The 32-year-old dropped to 5% body fat for his part in the film, shedding pounds and toning up by going on a low-carb diet and training in the gym every day for 12 weeks.

"I realised, when I was done with that movie, that I don't ever want to be in that good of shape again," Efron told YouTube series Hot Ones. "It was so hard.

"You're working with almost no wiggle room. You've got things like water under your skin that you're worrying about, making your six-pack into a four-pack, shit like that.

"It's just stupid. It's just not real. I'm happy that it worked, I'm happy that it got me through it."

Baywatch - based on the cult TV series of the same name - received almost universal disdain from critics but did gross $178 million (£145 million) at the worldwide box office.