Jack Whitehall has been ordered to bulk up for Hollywood.

The 33-year-old star was given a stern talking to by his agent after he stripped off to show his "pallid, flappy body" in an upcoming film and was told to do some work at the gym.

Speaking on the Manatomy podcast, Jack said: "I watched the first cut of a movie I did this year, and there's a sequence when I'm stripped and my clothes are ripped from me.

"My agent said, 'The movie's great – but you have really got to hit the gym. To be a really successful actor in this town, you've got to hit the gym.'

"He had been watching through gritted teeth thinking, 'Oh my God, why does my client look like that? Why is he so unashamedly willing to present that body to the world?'

The comedian added: "It hadn't crossed my mind. I'd watched my pallid, flappy body lolloping around and thought, yeah that's funny."

Despite his agent's criticism, Jack insists he is not "ashamed" of his body and is willing to get his kit off if it makes people laugh.

The 'Jungle Cruise' star said: "I'm very willing to get naked for a laugh, and make myself look quite vulgar.

"I'm not ashamed of my body. It's funny to shove yourself down into the dirt and humiliate yourself for a laugh."

Jack has forged a successful movie career but previously confessed that his old jokes could lead to him being cancelled by Hollywood.

He said: "I feel like I’ve definitely said jokes in the past that would be worthy of cancellation. I guess it’s how you weather that storm if it does ever come up.

"I’ve had it, sort of, occur a few times and I think, maybe, people are a little better now. We’ve had a few of these ridiculous cancellations of people because of historic jokes that — especially with a comedian because it was told in jest and the context of it was only ever intended as a joke — that you do tend to get away with it a little bit more.

"More so than you might with a tweet or a comment in an interview."