It says something about the gathering momentum of veganism that last week it breached not one but two bastions of British culinary culture. First there were complaints after that fanfare of eggs, butter and cream, The Great British Bake Off, was left with separated yolk on its face when its first vegan contestant, 19-year-old Freya Cox, was given animal products to use during a technical challenge.

Then Cadbury announced that from next month there would be a vegan alternative to its signature confectionery, the Dairy Milk chocolate bar. The Cadbury Plant Bar substitutes almond paste for the “glass and a half of milk” said to go into every Dairy Milk bar.

Both events made headlines because each, in their own small way, signalled the growing incursion of veganism into “normal” life. And nothing, other than perhaps a cup of tea (which is in any case increasingly made with oat milk), bespeaks normality in Britain more insistently than cakes and chocolate.

They were just the kinds of treats that for many years vegans were expected to forgo in their commitment to what was widely viewed as an ascetic lifestyle. But as well as having undergone its own gastronomic revolution, with a wealth of cookbooks and recipes from celebrity chefs, veganism has recently had a radical image overhaul.

“I used to think of vegans as pasty-faced and generally quite thin,” says 61-year-old Mike Harper, who became a vegan six years ago. A retiree in North Devon, he moved from a vegetarian to vegan diet under pressure from his daughters, and promptly completed an Ironman triathlon.

That old vegan profile, which Harper soon learned was false, has gone the way of Cranks restaurant and the cliche of nut roasts. In place of earnest caricatures like Keith in Mike Leigh’s 1976 Play for Today, Nuts in May, who liked to yawn on about the importance of chewing, there are now a host of celebrity figures – among them Bella Hadid, Lewis Hamilton, Joaquin Phoenix, Thandiwe Newton and Natalie Portman – presenting a far more media-friendly image of veganism.

Meat consumption in this country has declined by 17% over the past decade. The Economist magazine named 2019 “The Year of the Vegan”. And last year the World Health Organization recommended a plant-based diet for a healthy life. That endorsement, along with growing concerns about the impact of dairy farming on the environment, combined with the lifestyle rethink enabled by the lockdown, has significantly increased the number of people turning their backs on animal products in the UK.

The exact numbers of vegans are almost impossible to establish, but surveys have shown rapid growth. One suggested there had been a 40% increase in 2020, bringing the total to around 1.5 million. That is probably an overestimate, but certainly more than 500,000 pledged to eat vegan as part of this year’s Veganuary. As the figures swell so, of course, do the market and commercial opportunities.

It is not just the vegan convenience foods that now line supermarket shelves or the menu options in restaurants, but also the many ranges of clothing and cosmetics. It is now possible to buy non-leather Dr Martens boots and Hermes bags made from fungus, while Veja faux suede trainers triumphed in the fashion stakes four years ago.

Alice Adams, a novelist and ex-data analyst, says that there have always been non-animal clothing alternatives – if not necessarily fashion – but the labelling has changed.

“Now, you look at shoes and they’ll have a vegan label on them,” she says. “Anyway, leather has been superseded by other materials that perform better in things like running shoes and hiking boots.”

A lifelong vegetarian, she came to veganism over several years, before finally going all the way 15 years ago. “For most people,” she says, “it’s a process. For me, the cognitive dissonance just became too much and I finally tipped over the edge.”

In much the same way, veganism as a movement grew out of a schism in vegetarianism. In 1944, a few members of the British Vegetarian Society asked that a section of the society’s newsletter be set aside for those who also avoided eggs and dairy. When the request was flatly turned down, the secretary of the Leicester branch, Donald Watson, set up a new quarterly. He coined the term “vegan”, taking the first three and last two letters of vegetarian because, he declared, it marked “the beginning and end of vegetarian”.

The initial response was promising, attracting a correspondence of more than 100 supporters, among them George Bernard Shaw who promised to abandon eggs and dairy. Thereafter progress was slow, with the step from a meat-free diet to one without any animal products often proving a chasm.

Adams says that cheese is often the stumbling block. “Vegan cheese is mostly horrendous. There is good vegan cheese in the world. Miyoko’s in the US make amazing vegan cheese but it hasn’t reached the UK yet.”

When Verna Burgess, 57, from Hertfordshire, started out on veganism in the late 1980s, there was almost nothing available by way of substitutes. “You couldn’t even get ice-cream,” she recalls.

She remembers the gradual introduction of products and brands, and when the cafe in her local Waterstones introduced plant-extract milk she wrote a letter of gratitude to the manager. “I said: ‘Thank you very much. Now I can have a cappuccino.’”

For her, forgoing such pleasures was never a sacrifice because, as she puts it, she would just think of the animals’ suffering. If meat is murder, then dairy is torture, by the reckoning of most vegans. Increasingly, however, it is concern about carbon production and the environment that is driving a new generation towards a plant-based diet.

Chandu Gopalakrishnan, a sign-language interpreter, is 24 and became a vegan four years ago. “I originally did it more for environmental reasons,” she says, but then she went to a vegan festival where she wore a virtual reality headset that showed the life and death of a dairy cow. “It was really immersive and very moving to see something so innocent being so needlessly used,” she says.

While that experience has reinforced her veganism, the environment is still at the centre of her concerns. She would like to see a system introduced in which environmental impact was detailed on meat and dairy packaging, in the same way that health implications are displayed on cigarette packets.

“If it was side by side with a non-animal product that might be more expensive, then people could make an informed choice,” she says.

However Mike Harper would prefer to see a more interventionist approach from government.

“A lot of vegans I know are white middle class,” he points out. “But the fact is, if you’re on a low wage and you’re bringing up a family, then you’re going to go for the cheaper food option. But if the government subsidised non-meat products, then people would try them.”

It is hard to imagine a laissez-faire government with close ties to the traditional farming industry making that kind of move any time soon. For all the contemporary interest in veganism, the global demand for dairy products continues to rise, mostly as a result of population growth and the westernisation of diets in countries such as China and India. Set against that massive backdrop, the insensitivity of The Great British Bake Off production team or the introduction of a new chocolate bar hardly seem of great import.

Yet from such gestures and options spring new futures. A generation ago, vegans were dismissed as moralising bores. As the old joke went: “How do you known someone’s a vegan? Answer: They’ll tell you.” Today, a plant-based diet is seen by ever-increasing numbers of people as the only sensible way forward. In the years ahead even the most cheese-loving carnivores will have little choice but to consider it, if only as food for thought.

In numbers

79 million
The estimated number of vegans in the world

500,000
People who took part in Veganuary in the UK this year, up from 400,000 in 2020 and 250,000 in 2019

66%
The proportion of UK vegans who are female

163%
The increase in Deliveroo’s vegan orders in the UK in 2020 compared with 2019

55,000
The number of products with the Vegan Society’s vegan trademark, including 18,000 food and drink items

$24.3bn
The forecast size of the global vegan food market by 2026, with cosmetics worth $20.8bn

• This article was amended on 12 October 2021 because, due to an error introduced in the editing process, an earlier version gave Thandiwe Newton’s first name as “Thandie” whereas the actor reverted to its Zulu-derived spelling earlier this year.