Eating alone has become a defining feature of modern life: the breakfasting commuter; the household members with conflicting schedules; the widower who receives few visitors. Almost a third of British adults are eating alone “most or all of the time”, according to the latest Wellbeing Index, compiled with data from more than 8,000 people for Sainsbury’s by Oxford Economics and the National Centre for Social Research. Similarly, a Mintel survey of 2,000 UK consumers aged 16 and over has found that one in three are “regularly eating every meal alone”. In London, the figure rises to almost half.

Much of this solitary munching takes place behind closed doors. Single-occupancy homes are the second-most-common household size in Britain and a record 35% of over-16s are single, according to the Office for National Statistics. This is why, in 2018, Tesco announced plans to stock more than 400 single-portion products including burgers, steaks and vegetables.

As a nation, we have also become less self-conscious about solo dining. The bookings website OpenTable recently reported that reservations for one have increased across the UK by 160% since 2014. Bar seating and communal tables are increasingly popping up in restaurants.

While destigmatising solo dining in all its manifestations is liberating, our new dietary habits steer us into uncharted territory. Until now, eating in groups has been a universal human ritual. Not only is it practical (many hands make light work – and also reduce our vulnerability to predators) but meals have, traditionally, been used to meet our fundamental need for connection with others. It wouldn’t be making a giant leap to link eating alone with the current loneliness epidemic. One might also wonder if it is only a coincidence that this new phase is happening at the same time as rising obesity rates.

On a micro level, deciding what to have for dinner after a long day can be a challenge. “Eating alone has not only hugely changed how and what we eat but also how we talk to ourselves about eating,” says Bee Wilson, the author of The Way We Eat Now. “There’s a constant mismatch between a sense of how we should be eating and how we’re actually eating.” The multi-generational family meals of the Dolmio television ads are presented as the ideal, she says, but how many of us eat like that in real life, except for at Christmas? The default number that cookbook recipes serve is still four or six, but at least recipe writers have had to meet demand for meals you can throw together in minutes. Many of us are time-poor now, but when you are cooking for one you have to do the washing up as well. In 2010, Jamie Oliver wrote a book of 30-minute recipes, only to eclipse this in 2012 with a book of 15-minute meals. Some of his recipes even broke the 10-minute barrier in his 2017 bestseller, Five Ingredients, Quick and Easy Food. And behold the rise of the single-portion, five-minute chocolate mug cake, with its comforting, studenty appeal, which can be knocked up from scratch almost as easily as from the shop-bought mixes and is perfect for one.

Increasingly, ready meals are aimed at single households but, “as with any form of eating, there’s probably huge diversity in the ways people eat when they’re alone,” says Wilson. One way that younger generations are “squaring the circle of eating alone, enjoying food but not being enslaved to the kitchen is through the rise of meal prepping”, she says. Meal prep does not simply mean “preparing meals”. Rather it is a hashtag for an Instagram craze (10m posts and counting) for a borderline neurotically health-conscious version of batch cooking. “That has been a huge phenomenon,” says Wilson. “So many young millennials I speak to are going on about that book The Green Roasting Tin – you throw lots of delicious vegetables and herbs into a roasting tray, cook up a huge batch of it, then portion it up into tupperware boxes.”

The trend for eating alone has contributed to the popularity of dips such as hummus. Photograph: Getty Images/EyeEm

Less organised lone cooks (who aren’t flush enough to get expensive takeaways or ready meals every night) increasingly rely on what is known in my household as a “picky dinner”, which is more about curating a plate of food from the fridge and condiment cupboard than cooking. Wilson suspects that the boom in dips such as hummus and guacamole can at least partly be attributed to people eating on their own. “Things like that are so easy to eat if you’re simultaneously in a hurry and eating alone,” she says. “It’s a combination of getting into a habit of thinking it’s not worth cooking for yourself, and comfort.”

There is another factor that plays into the rise of solo dining. “In this world of convenience,” says Edward Bergen, global food and drink analyst at Mintel, “what we find is that mealtimes are becoming quicker. In Britain especially, consumers are spending less and less time, year on year, on meals.” In fact, he says, we are a nation of snackers, with 37% of us eating snacks instead of having a proper meal at least once a week. Millennials are the biggest snackers, taking shorter lunch breaks and relying instead on grab-and-go offerings (a booming market), from stodgy pastry products to porridge pots and healthy vegan wraps.

The glory of solitary eating is that you are free to savour your guilty pleasure without judgment. The New Yorker writer Rachel Syme recently triggered a mammoth confessional Twitter thread by admitting that when working from home alone she enjoys “a pickled beet in between a mini Babybel cheese sliced in half, eaten like a tiny sandwich”. Respondents shared their love of everything from tuna salad mixed with a packet of crisps to sucking bacon grease out of kitchen roll.

As the food and hospitality industries compete to service lone diners, the trend is increasingly presented as an aspirational consumer choice. Bergen says: “Of the people who often eat meals on their own, two thirds say mealtimes are a great way to have quality time to yourself.” In these busy times with blurred boundaries between work and leisure, me-time is certainly at a premium. However, as the 2017/18 Waitrose Food and Drink Report found, rather than luxuriate in our own company and take a moment to watch the world go by, many of us (23% of the 2,000 people surveyed) commune with our smartphones when eating out.

The rise of “food television” disturbingly encapsulates this disconnect. Otherwise known by its original South Korean name of mukbang, the phenomenon has become a source of fascination for Wilson. “People are watching videos of other people eating while they’re eating something completely unrelated,” she says. “It has also taken off in the US and people do it in the UK, too.” Usually, the presenters are beautiful young women who webcast themselves eating improbable quantities of food while inanely chatting about how delicious it is. “It’s about being kept company in some way we crave,” says Wilson, “and it’s a vicarious thing where you’re looking at someone eating this 6,000-calorie meal and that makes you feel better about the takeaway pizza that you’re eating by yourself at home.”

How you feel when eating alone can depend on whether or not you are doing so by choice. Bergen is an extrovert who says: “I don’t like eating alone, I love being with others.” I, on the other hand, am an introvert who works from home and has small children. One of my favourite things about travelling for work is going out for meals by myself.

Research by the Eden Project’s community-building initiative The Big Lunch found that, on the whole, people are not eating alone by choice, but rather as a result of “busy lives and hectic work schedules”. Furthermore, we are not happy about it. According to the Wellbeing Index, eating alone had the most negative impact on people’s reported wellbeing levels after having a mental health disorder.

Bergen says that the number of meals eaten alone is lower “for people who have kids living in their household, but not low enough. Often, one parent picks up the kids, cooks for the kids and then maybe has dinner themself, then the second parent comes home and has dinner later.” Solitary eating is rife, he says, among 16- to 24-year-olds, but is most common among the over-65s, with around half of those over 75 living alone. The University of Cambridge’s Centre for Diet and Activity Research found that over-50s who were single ate 2.3 fewer “vegetable products” daily. The data came from a cohort of 25,000 people over 40 whose diet and health has been logged since 1993. It also revealed that if widows and widowers lived with others, they ate as many vegetables as they would have done had they still been living with a spouse or partner.

But while eating alone can lead to a less healthy and diverse diet, it doesn’t necessarily make a difference to the healthiness of a meal, believes Mandy Saven of the trends intelligence company Stylus. “Decisions around health are far more complex than that,” she says. “We choose our food based on so many factors – what else have we eaten that day? Was a particular dish recommended by a trusted friend? How were we feeling on an emotional level?”

She also points out that many brands are making healthier ready meals, with a greater variety of nutritious ingredients. “We see the inclusion of more exotic and unusual ingredients that make these offers seem just as exciting as something that was cooked from scratch,” she says. For those who can afford it, meal-kit companies such as Mindful Chef and HelloFresh deliver all the ingredients for individual meals, and offer meals for one.

Eating alone with that modern substitute for a dining companion, the mobile phone. Photograph: Getty Images/Westend61

We tend to be more in control of what we eat when we eat by ourselves. The US psychologist John de Castro led a series of studies which showed that eating in company makes you eat more. He found that the bigger the party, the more you eat. At a dinner for two, you will eat around 35% more than you would alone, rising to a 75% increase for a party of four, and nearly twice as much at a table of seven.

It follows, therefore, that for those actively trying to lose weight, diet lapse is more likely when eating in company, as has recently been shown by researchers at the University of Pittsburgh. Research presented to the American Heart Association suggests dieters have a 60% chance of lapsing when eating with others. “Nobody understands why this social facilitation of intake happens,” says Suzanne Higgs, professor of the psychobiology of appetite at the University of Birmingham. “The other thing we don’t know is whether therefore eating in groups may contribute to increases in overall calorie intake and gaining weight over time.” Her team is currently investigating whether we compensate elsewhere in our daily food intake for large communal meals.

But a 2017 study from South Korea that was widely heralded as bad news for eating alone appeared to contradict the received wisdom that we consume less when alone. It found an association in men between regularly eating alone and a 45% greater risk of becoming obese. Like Japan, where you can eat ramen in a cubicle with an eye contact-blocking serving hatch, South Korea has taken dining out alone to the next level, and created a special portmanteau term for it – honbap – mixing the words for “alone” and “rice”. De Castro offers an explanation for the contradiction. “What we’ve found is that obese people don’t tend to overeat at home. Where they tend to overeat is outside of the home. In the Korean study, these are single men; they may be eating out a lot, and that can lead to overeating.”

Another obvious pitfall of lone dining is substituting real companions with smartphones or Netflix. “If you’re eating in front of the TV, that is often associated with greater consumption than sitting in the absence of any distractions,” says Higgs. Not only do we shovel more food into our mouths while we fixate on the screen, but we also go back later for significantly more. Rather than anaesthetising the experience of eating alone with screens, Wilson believes we should be celebrating it. “It’s a wonderful, joyous, great way to eat where you can get to know your own tastes and you don’t need to please anyone except for yourself.”