If you consumed a lot of news last year, you’d be forgiven for thinking that strawberry yoghurt wants to murder you. Since last spring, a new obsession has spread across Britain: have you heard? Don’t you know? UPF is our new food enemy. What is UPF? It is ultra-processed food. What is ultra-processed food? It can include cereal and sausages and fruit-flavoured yoghurts and instant soup. How exactly can I determine if something is ultra-murderous? Anecdotally, my friends don’t seem to know the definition of UPF – but they do know they should be afraid of it. Another person who, by his own admission, hasn’t quite mastered the definition is Chris van Tulleken, the infectious diseases doctor who wrote the bestselling book Ultra-Processed People: Why Do We All Eat Stuff That Isn’t Food … and Why Can’t We Stop? At the beginning of his book, he forgoes “a long formal scientific definition” of UPF, instead arguing it can be boiled down to this: “If it’s wrapped in plastic and has at least one ingredient that you wouldn’t usually find in a standard home kitchen, it’s UPF.” Later, Van Tulleken and his brother debate whether a Marks & Spencer sausage roll is UPF – his brother thinks it is, because he doesn’t have pasteurised egg and calcium carbonate at home. Yet he says calcium carbonate doesn’t count because “it’s added by law to most white wheat flour”. Instead, he questions the snack’s “purpose” – another way he defines UPF is as something marketed “aggressively” for “no other reason than financial gain”. This seemingly leaves Van Tulleken just as confused as the rest of us – “to be fair” to his brother, he writes, “I find myself having these same debates internally all the time.” Herein lies the problem with the current focus on UPF. It is fundamentally muddled. It’s not that studies about UPF haven’t already had troubling results – one randomised controlled trial found that people on UPF diets ate more calories and gained more weight than those on unprocessed diets. It’s that while scientists use somewhat more rigorous definitions of UPF for their trials, these definitions are not universally standardised or agreed upon and are often ambiguous, making things confusing for consumers. The shiny, slippery new category of UPF, and the news of its associated evils, implies that a protein-packed yoghurt is just as likely to cause heart disease as a frozen pizza, just because both come wrapped in plastic and contain xanthan gum. Where does that leave us? Are we supposed to be afraid of everything in a packet and hate ourselves for eating it? This isn’t what Van Tulleken wants. He notes that there is likely “a spectrum” of UPF and possible harms, and concludes “Whatever happens, don’t beat yourself up.” But with worries about UPF amplified across the media, I think this is a tough ask as long as its very definition remains vague. What happens when someone thinks their favourite strawberry yoghurt will cause them to have a stroke? Do they suddenly magically find the time to make their own, healthier version from scratch? Do they miraculously start being able to afford the more natural, organic yoghurt they’ve always hated the taste of? It’s not that I think it’s wrong to question our current food culture, or that we won’t one day identify a mechanism involved in food processing or an additive in UPF that is inherently harmful. It’s just that I think it’s too early and things are too uncertain for us to descend into panic. In July, the government’s scientific advisory committee on nutrition (SACN) said “there are uncertainties around the quality of evidence” that links UPF with adverse health outcomes such as heart disease, cancer and depression. The committee warned that many UPF studies did not take confounding variables – such as a person’s smoking history or calorific intake – into account. “The evidence to date needs to be treated with caution,” it said. Then, in November, a WHO-backed study found that some UPF is actually good for our health, with the fibre in bread and cereal associated with a reduced risk of developing cancer, heart disease and diabetes. The fact that new information like this is emerging all the time means I think we should wait to know more before we scare consumers into emptying their shopping baskets. My view is coloured by my history of having had an eating disorder – I had anorexia as a teen and am now recovered, so I am very aware of the dangers of mixing food and fear. The UPF hype reminds me of the “clean eating” trend that dominated social media in the 2010s. Some advocates cut out entire food groups in an attempt to be “healthy”, and former clean eating influencers have said that the fad led them to spiral into eating disorders. Duane Mellor, a registered dietitian and nutrition researcher at Aston Medical School, says he has seen “increasing” reports that some individuals “are starting to avoid UPFs and not managing to meet their nutrient needs, putting their health further at risk”. The nutritionist believes that we should promote healthy foods rather than stigmatise the foods that many people rely on (a 2021 Australian study found that poorer people ate more UPF). “Rather than arguing about the fine details of which foods or ingredients need to be avoided,” Mellor says, we should emphasise healthy foods, “as largely there is agreement about the foods we should eat more of, which are vegetables, fruits, nuts, seeds and legumes.” Researchers and writers raising the alarm about UPF often call for greater regulation of the food industry and a world in which consumers are more informed. It is an admirable aim, but I wonder whether the UPF classification is even the best avenue for change. We already know so much about how foods high in fat, salt or sugar affect our health – shouldn’t we go further with regulations here? I can’t understand why consumers should feel guilty for ignoring a warning label when supermarkets simply shouldn’t be allowed to sell a sandwich containing 50% of your daily salt intake. We live in a world where consumers are blamed for companies’ poor choices. Sometimes, I feel I can’t go a day without people telling me about something I should or shouldn’t eat – and I’ve lived long enough to see some of these claims reversed (a glass of red wine is actually bad for you, cheese is actually good for you, the egg thing is complicated). I wish everyone had enough time and money to make the happiest and healthiest choice about food for themselves, but that isn’t the case. While we fight food inequality and push for further regulation, there is a fine line between educating people and terrifying them. That line might be arbitrary – but, then again, so are many definitions of UPF. Amelia Tait is a freelance journalist