My friend recently met a man on a dating app and went out for dinner with him. When he arrived, the man announced that he didn’t drink. Nothing unusual about that: plenty of young men are abstemious these days. His next declaration was more surprising: he didn’t eat. Instead, he lived off something called ‘Huel’.

Huel — an abbreviation of ‘human fuel’ — is a type of powdered food made of oats, peas, flax and rice. I’ve tried it and it is disgusting — gruel, essentially, in smart packaging. But it’s hugely popular: Huel is now one of the fastest growing companies in Britain. Huel is low in fat and high on principle. ‘We live in difficult times,’ says its evangelical marketing bumf. Meat is ‘inefficient, unsustainable and can be inhumane’. The world’s population is growing and ‘if everyone ate a western diet, we’d be in even bigger trouble’. Huel ‘offers a solution’.

The Huel fad taps into a deeper phenomenon among men of my generation, a new sort of narcissism. Young men are increasingly obsessed with self-discipline and self-improvement and the self all round. Vanity is as old as humanity, of course, as is self-restraint. But the new narcissism is about being vain and virtuous at the same time.

Young men are drinking less alcohol, smoking less and, oddly, having less sex, perhaps because sex involves focusing on someone else. Traditional masculine pursuits are being abandoned in favour of more ethical ones. Pubs are closing down and gyms are opening up. ‘Fitness’ and ‘wellness’ are the buzzwords, and personal trainers are the new gurus, encouraging their diligent clients to be in good shape for their #gymselfies.

It used to be women who were battered with dieting advice and who were flogged endless piles of self-help books. A few years ago, ‘clean eating’ was in vogue. Happiness was just round the corner, we were led to believe, so long as we stuck to a diet of chia-seed smoothies and no gluten.

Nowadays, male self-improvement is all the rage and men are now almost as boring about their appearance as women. Bodybuilding, not so long ago a peculiar pursuit, has become a very ordinary hobby and the market for protein products is enormous and swelling: it is currently estimated to be worth £238 million and set to reach £409 million by next year. Supermarket shelves now groan with ‘fuel bars’. According to the Office for National Statistics, protein supplements, once a niche fitness product, are now a staple in the nation’s shopping basket.

Meanwhile, everyone — male or female — extols the virtues of veganism. Last year, the F1 racing driver Lewis Hamilton announced he was going ‘plant-based’ because of his fears for the planet. Veganism is on trend because it is slimming and ethical — never mind that it makes you a bore at parties.

We are witnessing a very 21st-century asceticism. No real sacrifice involved, just a new exciting set of powders and pills to order on Amazon Prime, while you have earnest conversations about the dangers of our consumer culture.

So why are these young men turning into narcissists? What’s with the almost religious zeal? It can’t be a coincidence that the rise in lean, ethical dieting has come during the era of the #MeToo movement. Men are being led to believe that their masculinity is a problem. Their rapacious pursuit of pleasure has damaged the world around them, they are told — and it’s up to them to curb their appetites. Women have had enough.

For an example of an unacceptable male appetite, look at the US President. Donald J. Trump is held up as a symbol of all male vice, with his pussy-grabbing and his populism. A serial womaniser and fast-food addict, he’s a greedy man. Harvey Weinstein, another #MeToo villain, is invariably described as a fat slob who was addicted to sex, fizzy drinks and bad food. They have become symbols of ‘toxic masculinity’. Is it any wonder that many young men are starting to look for ways to, as that dieting cliché goes, ‘detox’ their masculinity — in order to distance themselves from monsters like this?

There are heroes to emulate, too. Look at Jordan Peterson, the Canadian psychologist. He has become famous for offering self-help advice to young men who feel lost in the modern world. His message — that men can be tougher than they think — has proved popular, as has his demolition of various feminists. His message to men is to be proud of their sex.

But he too is diet-obsessed. He eats almost nothing but meat and green vegetables. While he doesn’t exactly tell his followers what to eat, he espouses a ‘zero-carb’ carnivore diet. His daughter, Mikhaila, details his food habits on her blog. Her father says his regime has delivered ‘excellent results’ and helped him combat various autoimmune conditions and depression. One of the terms Peterson uses is ‘carbohydrate poisoning’. So even a celebrity sage who rails against the emasculation of modern men is preaching a message of restricted consumption and fewer carbs.

Then look at the tech superstars in Silicon Valley. These are the richest, most powerful men in the world: the new aristocracy. But whereas powerful men of the past have had a lovely time indulging themselves, these new supermen are intoxicated only by abstemiousness and their own carefully structured diets. Steve Jobs used to eat a fruitarian diet, consisting mainly of apples and carrots. Peter Thiel goes ‘back and forth’ on to the paleo diet and says one should ‘not eat sugar’. Google chief Bill Maris eats a strict vegan diet and takes a hundred pills a day so he can ‘live long enough not to die’.

Immortality is the latest obsession in Silicon Valley. The fashionable pastime for tech whizz kids is to attempt to ‘cure’ death — and conquer their own mortality. It is the ultimate narcissistic pursuit. Thiel and Elon Musk have embraced transhumanism, an intellectual movement which believes in the body’s ability to evolve beyond human limits. Some transhumanists fantasise about cutting out food and sex entirely. If man can overcome his desire for both, he will be one step closer to becoming a machine — or even a god. ‘The less you eat, the better. You’re better off being borderline starving to live longer,’ says Zoltan Istvan, a transhumanist politician who is running to be the governor of California later this year. For breakfast, he eats artificial eggs made out of peas and beans.

Food replacement products originated in America’s tech community. They were dreamt up as a way of replacing normal food with something more sustainable and convenient. In 2013, Rob Rhinehart, an American software engineer, launched Soylent. In a blog post entitled ‘How I stopped eating food’, Rhinehart argued that regular food was outdated and expensive. His meal--substitute drink had transformed his body (‘my skin is clearer, my teeth whiter, my hair thicker’), improved his happiness and reduced his spending. It also made him rich. The company is now worth $100 million.

These diets and food substitutes are certainly eccentric —the sort of sci-fi whimsy that tech billionaires can indulge in — but they are alarmingly popular. The idea that the male body should be purged and perfected has become a mainstream one. What would once have been called male anorexia (‘manorexia’) is now sold as an advanced, high-tech ‘disruptive’ diet.

And technology makes it easy to participate in the new narcissism. Health apps and wearable tech let the self-obsessed track every mind-numbingly dull detail of their routine: steps taken, heart rate, sleeping patterns. Sites like Instagram are full of pictures of gym-toned, protein-slurping men. Anyone who watched the reality TV show Love Island will be familiar with the sight of topless, hairless, preening men with eight-packs and fake white teeth who are as obsessed with their own bodies as the women who surround them, if not more so. All-male beauty salons are now a common sight on the high street. In a recent interview, Eric Anderson — a professor of masculinity, sexuality and sport at a British university — explained why men were willing to indulge in what he referred to as ‘self-care’. It was, he said, because of a ‘softening of men and their gender more broadly’.

This shift in traditional gender stereotypes may also explain why women now feel comfortable commenting on male bodies, while the opposite is frowned upon. Writing for the Times recently, Anna Murphy described how she preferred the bodies of men who do yoga. It makes men look ‘stronger, leaner and a lot sexier’, she said. Stronger, leaner, sexier. What man wouldn’t want to seem like that to a woman? And what man would now dare to say such a thing about women’s bodies?

There is a dark side to the modern male fixation on intensive self-improvement and ethical dieting. In July last year, the NHS reported a 70 per cent rise in adult men being admitted to hospital with an eating disorder. Around the same time, it was revealed that steroid use had quadrupled. Up to a million people in the UK now take anabolic steroids in order to make themselves look more muscular — and one in ten men who go to a gym are thought to have ‘muscle dysmorphia’: the neurotic belief that their bodies are insufficiently toned.

The Huel-slurping puritans, the Silicon Valley transhumanists and the hairless gym bunnies have something in common: an obsession with pushing the limits of their bodies. They want to become virtuous machines, a superior breed of man to the #MeToo monsters who have given masculinity such a bad name. Whether they will find love and happiness at the end of all that devotion to themselves is a different matter. I don’t think it will come as much of a surprise to learn that my friend didn’t say yes to a second date.

The idea that the male body should be purged and perfected has become a mainstream one

Spectator.co.uk/podcast Lara Prendergast and Tom Reader on lean eating and Huel.