Bear Grylls 'embarrassed' by his former vegan lifestyle: 'It's wrong'

Grylls is even now a spokesperson for beef organ supplements Ancestral Supplements.

"I was vegan quite a few years ago – in fact I wrote a vegan cookbook, and I feel a bit embarrassed because I really promoted that,” Grylls said.

"I thought that was good for the environment and I thought it was good for my health.

"And through time and experience and knowledge and study, I realised I was wrong on both counts."

Grylls said that he wasn't telling other people what their diet should be but merely reflecting on his own experience.

He said that Britons should go on "their own journey" to find out what works for them.

The adventurer explained that for the last two years he’s been trying to eat more naturally – avoiding processed foods, bread, pasta and even vegetables, and enjoying a diet favoured by our ancestors thousands of years ago.

The 48-year-old added: "For a long time, I’d been eating so many vegetables thinking it was doing me good, but just never felt like it had given me any good nutrients compared to the nutrient density I get from basically blood or bone marrow – red meat.

"I’ve tried to listen to my body more, tried to listen to nature, and I don’t miss vegetables at all.

"I don’t go near them and I’ve never felt stronger, my skin’s never been better, and my gut’s never been better.

"I’ve found a counterculture way of living, of embracing red meat and organs – natural food just like our millennia of ancestors would have eaten for hundreds of thousands of years.

"And out of all the different things I do for my health, I think that’s probably been the biggest game-changer, in the sense of improving my vitality, wellbeing, strength, skin and gut.

"It’s just been getting away from the processed stuff and making the predominant thing in my diet red meat and liver and the natural stuff – fruit, honey, that sort of thing. It’s just about finding a more ancestral way of living."