I’m sure he’ll forgive my bluntness, but Bear Grylls was never the most convincing vegan.

Greta Thunberg, yes. She has been vegan since the age of 10 and, when not giving world leaders the metaphorical finger for their contemptuous disinclination to address climate change properly, has worked with vegan charity Mercy For Animals.

Alan Cumming, yes. Ahead of the COP26 climate conference in Glasgow he wrote to conference president Alok Sharma MP to ask that only vegan food be fed to delegates. To do otherwise, he argued, was “like serving beer at an Alcoholics Anonymous meeting.” Mine’s a lager then said Mr Sharma, before dishing out a predominantly meat-based menu.

Natalie Portman, yes. She walks the walk, has the t-shirt and probably even watches TED talks.

And Lewis Hamilton. He went vegan in 2019 – “The only thing I regret is not having done it before” – and has a chain of vegan restaurants called Neat Burger. London is stuffed with them, there’s one in Dubai and the first New York branch opened last month.

But Mr Grylls? Not so much. After all, if you believe the 11 Living Things Bear Grylls Has Eaten list I found down the back of the internet, this is a man who has in his time bitten the head off a snake, snacked on yak eyeballs and goat testicles, and chomped down on raw moose heart. Not for nothing is the 48-year-old’s profession often given as ‘adventurer’ or ‘motivational speaker’ (I mean you’d need the after-dinner speech equivalent of a gun to your head to eat raw moose heart, right?).

So it’s not much of a surprise to learn the Old Etonian has recanted. He has turned his back on his vegan faith. He has gone full carnivore and now seems to exist on a diet of meat, blood and bone marrow. Oh, and no vegetables at all if he can help it.

Unsurprisingly, he says he now feels a little red-faced about ever pushing a plant-based diet. Especially in print.

“I wrote a vegan cookbook, and I feel a bit embarrassed because I really promoted that,” he said in an interview with the Press Association last week. “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.

“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.”

Mr Grylls was speaking in his capacity as spokesperson for something called Ancestral Supplements. It’s a US-based firm which launched in the UK last month. It uses beef raised in New Zealand to manufacture what it calls “nutrient-dense superfoods in supplement form”. Products available include Grass Fed Beef Liver, Grass Fed Beef Heart and Grass Fed Spleen. They sell for £52, £56 and £58 per bottle respectively.

To put that in perspective, my handy GB Deadweight Cattle Prices By Region reckoner tells me that in Scotland £500 gets you a whole cow. That’s post-slaughter by the way, so you don’t even have to kill it yourself.

The company’s claim is that organ supplements are “increasingly being embraced” to bolster immunity, reduce fatigue and add nutrients missing from the modern diet. Quoted in a promotional release, Mr Grylls describes how his “interest” in eating “organ meats” (or offal, if you prefer) began when his eldest son was struggling with low energy, and skin and stomach complaints. Mr Grylls himself had painful kidneys. At the time, both were vegan. After consulting a nutritionist, father and son went back onto the red stuff. The transformation was “super-fast” he says.

“I’ve found a counterculture way of living, of embracing red meat and organs – natural food just like our ancestors would have eaten for hundreds of thousands of years,” he says in the interview. “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, well-being, strength, skin and gut.”

READ MORE: NIGELLA ONLY LASTED TWO WEEKS AS A VEGAN

You can’t contradict Mr Grylls’s experience of his own body, its reaction to certain foodstuffs, and the benefits he feels from adopting a new diet. However he has certainly changed his tune.

In 2015 he published a cookery book titled Fuel For Life (available in all good charity shops). It featured dairy-free recipes alongside ideas for vegan dishes such as bean burgers. In it he writes: “Many people think I must be a massive meat-eater. I’m not. To satisfy our insatiable appetite for meat we have developed very unnatural ways of breeding, keeping and killing animals. This far exceeds our nutritional needs for the health of myself and my family.”

So where does this leave veganism? Clearly Mr Grylls was hardly its most steadfast champion. It’s difficult to talk health benefits or morality with a snake’s head in your mouth. Harder still to be taken seriously. But his U-turn puts the issue on the table (sorry), and at a time when veganism is more popular (and therefore more divisive) than ever.

According to one estimate there are 88 million vegans in the world, around 1.1% of the global population. The Vegan Society puts the number of UK vegans at 600,000, or 1.2% of the UK population. But that’s a fourfold increase since 2014, a rise helped by initiatives such as Veganuary, where people are asked to give up meat and animal products in January. Moreover 2.7 million British households contain at least one vegan or vegetarian. There are only 19 million households in total and only five million with one or more dependent children. So everyone knows a vegan – particularly if they know a Gen Z-er or a student. And particularly if they are a student.

In February, students at Cambridge University voted to ban meat and dairy products. Meanwhile Stirling University will serve only plant-based foods by 2025. However a campaign by pressure group Plant-Based Universities to bring about a similar ban at Edinburgh University fell when only 19% of students who voted back the plan. Among those speaking out against the motion was the Countryside Alliance. So yes, as ever there’s a whiff of the culture wars about this, a hint of the old personal freedom versus collective responsibility conundrum.

Of course we can argue about the pros and cons of a vegan diet until the cows come home (alternative plant-based idioms are available).

Those who aren’t vegan and who have an opinion will point to various perceived nutritional deficits, such as the difficulty of taking in enough protein. Even the official advice for vegans on the NHS website warns: “If you do not plan your diet properly, you could miss out on essential nutrients, such as calciumironvitamin B12iodine and selenium.” Others will point to concerns that vegan diets can be used to mask eating disorders.

Contrarily, those who do follow a vegan diet will testify to the health benefits they feel. They will educate/enlighten/bore you with facts about the (admittedly unconscionable) practices of the chicken-rearing industry, about battery farming, wool production and salmon farming. And they will point out the extreme environmental damage caused by beef production in particular, and its contribution to the climate emergency.

Who’s right? Who knows. But I have a hunch.

“The arc of the moral universe is long, but it bends toward justice.” Martin Luther King Jr says that in his I Have A Dream Speech. It may seem trite to apply it to cows, sheep, chickens and pigs, misguided to extend to animals the concept of justice as it pertains to humans. But many would. Ditto climate justice, the fight for the rights of those most vulnerable to the effects of climate change. Veganism is a subset of both. Which brings us back to Greta Thunberg. What else could she eat but plants and nuts?

A few more questions: do you need to be a radical, an outlier, a thrower of paint over women who wear furs to believe that in 50 years the raising of animals for consumption will be illegal? Is the moral universe arcing towards a world of sustainably sourced jackfruit burgers and eco-friendly soya milkshakes? And if you answered first no and then yes, are you a hypocrite for sitting down to a chicken dinner this evening?

Answer when you feel you can. Until then, Bear Grylls will enjoy his bone marrow and Grass Fed Spleen supplements untroubled, and feel all the better for it.