Health experts have ramped up calls to improve the national diet in the wake of research that paints a worrying picture of the harms linked to the consumption of ultra-processed food (UPF). Doctors, scientists and dieticians say a wide-ranging and comprehensive effort is needed to boost public health, with strategies to combat the aggressive marketing of UPF, remove the food industry’s influence over policymaking and make sure healthy foods are affordable, accessible and enjoyable. “We have a food system driven by profit and cost and that makes it a challenge, but the solutions are out there,” said Duane Mellor, a dietician and senior lecturer at Aston University. “It’s not an unsolvable problem.” Concern over the national diet has been fuelled by recent studies linking UPF to raised blood pressure, heart attacks and strokes – findings described as a wake-up call for governments worldwide. Previously, researchers have found higher rates of heart disease, obesity and some cancers in those who eat the most UPF. Research on UPF typically adopts the Nova classification developed by Brazilian researchers more than a decade ago. It groups foods according to how much they are processed. Group one foods are minimally processed or unprocessed such as whole fruit and vegetables, fresh meat and fish. Group two foods are processed ingredients such as salt, sugar and oils. Group three covers processed foods such as tinned fruit and vegetables. Group four are the ultra-processed foods: sweet and savoury snacks, ready meals, soft drinks and other items that often have little if any intact food from group one. On average, UPF makes up half of the UK diet. The Nova classification is not perfect. Mellor points out that wholemeal and wholegrain bread from the supermarket count as UPF but are “probably not what we should be worrying about”. Most bread is made by the Chorleywood process, which uses fats and emulsifiers so more water and lower-protein flours can be used. And many foods classified as UPF are those high in salt, fat and sugar, for which dietary guidance already exists, he adds. Despite its shortcomings, the Nova classification has driven a surge in research. The vast majority are observational studies that look for associations between UPF and poor health in populations, but cannot prove that consumption is to blame. This shortcoming, common to nearly all nutritional research, leads to uncertainty – and uncertainty leads to inaction. In July, the government’s scientific advisory committee on nutrition noted that while the evidence around UPF causing harm was “concerning”, the limitations of Nova and other potential explanations for ill-health – such as people with poor lifestyles eating more UPF – meant the findings should be treated with caution. But others want action now. “We urgently need to advise people to reduce consumption of UPF in our national dietary guidance,” said Chris van Tulleken, an expert on UPF and author of the bestselling book Ultra Processed People. “Globally, poor diet is the leading risk factor for early death and cardiovascular disease, and the evidence shows that poor diet means a diet high in UPF.” He wants black warning labels on UPF, a move adopted in Chile and Mexico. Elling Bere, a professor of public health at the University of Agder in Norway, agrees there are weaknesses in UPF research, but believes the evidence is strong enough to warrant warnings. He and Dr Filippa Juul at New York University were asked to review the health effects of UPF and make recommendations for this year’s Nordic Nutritional Recommendations (NNR). On the basis of the review, Bere and Juul said the NNR should advise people to limit their consumption of UPF. The advice was turned down after it was opened for public consultation. The decision drew accusations of food industry influence, which the NNR strongly deny. “I was surprised because we just summed up the literature,” said Bere. “As far as I can see, the science behind the advice on eating red meat is no stronger than for UPF and they say don’t eat more than 350g of red meat a week. There’s not even a qualitative recommendation on UPF. We should think about the precautionary principle.” How UPF might cause ill health is still being untangled. The foods tend to be high in fat, salt and sugar; they are energy dense, but poor in fibre and other nutrients. They contain emulsifiers, preservatives, gelling agents and artificial colours and flavours. One of the most famous studies in the field, led by Kevin Hall at the US National Institute for Diabetes and Digestive and Kidney Diseases in Maryland, found that people on a UPF diet over-consumed and put on weight compared with those who ate less processed food. Processing itself may be an issue, by destroying nutrients and making it easier for the body to absorb calories. “It looks like there is something in the processing that is not good for us,” said Bere. Mellor argues that public health campaigns should focus on promoting healthy diets rather than stressing the harms of UPF. He wants more social community cooking spaces where people can make and buy inexpensive, healthy meals made from ingredients that would otherwise go to waste. “We can have healthy street food outlets and a pay-as-you-can approach,” he says. Smart marketing strategies are also needed, he adds, to show that healthy foods can be quick, enjoyable and affordable. In the face of industry power, the challenge appears substantial. “We need to remove the influence of the industry,” says van Tulleken. “Until the major charities that inform policy, the research groups doing dietary health research, and the doctors and scientists that write in the media stop taking money from the food industry, very little will change. Just like tobacco, we need to see UPF company money as dirty.”