“Let me ask you a question: how many calories do you think the average woman should have each day?” says Herman Pontzer, a professor of evolutionary anthropology at Duke University whose specialism is metabolism. For a moment, I’m surprised. I’m the one supposed to be asking questions here—and besides, isn’t the answer widely known?
“2,000,” I reply, warily. “No!” he says, triumphantly. “Women burn around 2,400. Men, around 3,000. These figures are based on thousands of measurements, taken around the world. So when you look at calories on a label or menu and decide what you can eat based on an intake of 2,000, you’re starting with a made-up number. There’s no added information in knowing the calories.” In short, when it comes to calories, people aren’t very well equipped to add up.
But does it mean that they shouldn’t bother? That is the question begged by the government’s new rule that, from April, restaurants, takeaways and cafés with over 250 employees must showcase their calories. The reasoning behind it is simple enough: to help consumers make healthier decisions and encourage businesses to offer lower calorie options. The reality is, as ever, slightly more complex.
Let’s start with the hard facts: eating more calories than you burn leads to weight gain. Being overweight or obese—as 64 per cent of adults in the UK are, as of 2019—is a risk factor for all sorts of diseases, and obesity costs the NHS billions of pounds each year. In that respect, says Herman, the measure gets one thing right: “Weight is affected by the calories you are eating, so there is sense in society focusing on calories. I like the idea that if people knew more, they would make good choices.” The problem, he continues, is that “there is no evidence that that’s true”.
On the contrary, in the US, where calories have been mandated on restaurant menus since 2018, obesity has continued to increase steadily. In New York, it seemed these menus encouraged some people to order dishes with more calories, not fewer—perhaps in a bid to get value for money, or—my personal theory—from a “fuck it” mentality. “I don’t know why. I’m not a psychologist. But the idea that people are overeating just because they don’t know the calories? I’m really not sure,” says Pontzer, whose latest book on metabolism, Burn, draws on 20 years of meticulous research into what happens to the energy we consume.
As Anthony Warner, a former food industry development chef and the author of The Angry Chef: Bad Science and the Truth About Healthy Eating, points out, “People are not going to be going into a burger restaurant and saying, I didn’t realise there were a massive number of calories in fried and side dishes.” By the same token, knowing how many calories there are in a chocolate digestive doesn’t stop me from taking several more. It’s a source of regret afterwards, of course, when I check the half-empty packet and confirm what I knew already—but when it came to the crunch, that knowledge didn’t change my behaviour. “Already several of the big chain restaurants offer calorie labelling on their website or on their menus,” says Warner, “and I’ve not consistently seen evidence of benefit.”
“People are not going to be going into a burger restaurant and saying, I didn’t realise there were a massive number of calories in fried and side dishes”
The reasons for that are myriad. Obesity is a complex, systemic issue, and has more to do with economics, society and the way in which certain foods are processed than it does individual choice. “The things that will improve obesity will be lifting people up socially and economically, [and] addressing systemic problems, rather than making people feel guilty about calories,” says Warner. A far more effective way for big restaurant chains to tackle obesity would, to his mind, be “improving working conditions and paying people more”.
The reason I take another biscuit (and another) is partly individual, but it also illustrates one of the wider problems fuelling weight gain, which is that certain foods lead to overeating. The last 70 years has seen ultra-processed food—that is, loosely, food made with additives or “industrial formulations” wherein flavour, sugar, fats or chemical preservatives are added—become increasingly prevalent in our diets, and these foods are more or less designed to make us want more. “The issue is not that you’re having an extra 500-calorie meal every day. Most people don’t do that. It’s consuming foods that trick our brains into overeating, which is more subconscious and a very slippery thing to get hold of,” says Pontzer. I take another biscuit because those biscuits are, in his words, “flavour-engineered to be over-consumed”.
They are low in filling fibre. They have pleasing textures, strong flavours, and are both speedy and cheap. “We still don’t really know what it is about ultra-processed food that generates weight gain,” investigative food journalist and author Bee Wilson wrote in The Guardian in 2020, but “evidence now suggests that diets heavy in ultra-processed foods can cause overeating and obesity… regardless of sugar content”. It is fashionable, these days, to point the finger at sugar, just as it was fashionable 10 years ago to point at fat—but, as Wilson observes, singling out individual nutrients as problematic simply causes the producers of ultra-processed foods to tweak their products to fit the fashion: turning the “low fat” products of a decade ago into “sugar free” versions and diverting the attention away from the real villain.
“One day it will be protein,” Pontzer says wryly. “This villainising of particular nutrients isn’t helpful. I’m not defending sugar, but sugar itself isn’t what leads to weight gain.” What does is excess calories, but if you’re eating foods which aren’t highly processed and are high in fibre, the chances of you overdoing it are slim. “No one will get fat from overeating broccoli. I am willing to stake my career on that claim,” he laughs. “It’s not flavour-engineered to be over-consumed, it’s low in calories and it’s full of plant proteins and fibre which make you feel sated.” A whole bowl of broccoli will have more calories than a single crisp, he continues, but you aren’t likely to order a second and third bowl of it. Whoever stopped at a single crisp?
The problem with any one measure—sugar, fat or calorie counts—is that it fails to take into account a meal in its totality. That’s why, for Thomasina Miers, co-founder of the Mexican chain Wahaca, calorie counts are “such a blunt tool”. “It makes no reference to fibre when it’s the lack of fibre in our diets that is causing so many problems. It makes no reference to nutritional quality. It makes no reference to carbon footprint”—which of course has no bearing whatsoever on weight gain but is not unimportant in the grand scheme of things. On the basis of calories alone, a diner at Wahaca might avoid their bean and feta tostada—but not only is it one of the most sustainable dishes on the menu, it is “rich in protein, fibre, and essential minerals, and made with local pulses”.

Jemima Jones and Lucy Carr-Ellison are former models who run Wild by Tart and Tart London: a restaurant and catering company frequented by those in fashion and the arts as much as punters in love with their aubergine and cashew satay. “Cooking wholesome but healthy food is a huge part of what we do,” says Jones. “Some restaurants need to do a lot more to help their customers eat consciously. However, a lot of us in the food industry are already very conscious about what we’re serving. You can cook delicious but healthy food, you just need to rely on sustainably and seasonally sourced ingredients, rather than calorie numbers.”
“There is a law in economics which says when a measure becomes a target, it ceases to be a useful measure. By targeting calories explicitly, that measure stops being useful,” says Warner. The aim of the government and food industry should be to “make food better, rather than better at meeting targets”. The latter just leads to certain companies gaming the system: serving the same size portion of fries, but recommending they are for two people, for example, or reducing the calories by replacing say, fibre, with liquid. Pontzer agrees: “It would be nice if they reduced the calories by not taking the fibre out or reducing the protein, but I don’t expect the food industry to act responsibly,” he says dryly. “They’re in the business of making money.”
You can cook delicious but healthy food, you just need to rely on sustainably and seasonally sourced ingredients, rather than calorie numbers”
There is another, less obvious but more insidious side of this focus on calories, which is that the people most likely to take note of calorie counts are those for whom they are profoundly unhelpful: namely those with or recovering from eating disorders. As a former sufferer myself, I know all too well how stress-inducing those little numbers can be. The idea that eating out could be made even more stressful for 1.25 million people—which is merely an estimate of the number of people currently afflicted with eating disorders in Britain—is deeply dispiriting. As Tom Quinn, director of external communications at BEAT, the country’s leading eating disorder charity, points out: “Calorie counting can cause people with binge eating disorder to experience guilt and distress, and people with anorexia can become more fixated on restricting their food intake. There is also limited evidence that adding calories to menus helps to address obesity.”
But it is not just people with eating disorders who will have their meals out marred by this move; it is most of us, because above all else, eating out is supposed to be an enjoyable experience. As Miers points out, people don’t come to Wahaca for a buttermilk chicken taco and a brownie on the regular, they come “as a treat, two or three times a year”. Whether you’re a model, a middle-aged man with a dad bod or anything in between, eating out should be about “creating social bonds, relaxing and celebrating”, says Warner vehemently. Is calorie counting ever actually helpful? For some people, sometimes. But eating is about so much more.