Is it time to take action against ultra-processed foods, asks Nick Hughes
‘Why do we all eat stuff that isn’t food – and why can’t we stop?’ That was the provocative question posed on the front cover of Dr Chris van Tulleken’s best-selling book Ultra-processed people, in which the medical doctor and TV presenter made the case for the damage to our health caused by diets high in so-called ultra-processed foods (UPFs).
The book’s publication in the spring of 2023 raised the temperature on a global debate that had been simmering for a number of years. The question at its heart is this: are UPFs, which include most mass-produced baked goods, cereals, snacks and other convenience food products, inherently bad for our health due to the structural changes that occur during their processing, or are there bad UPFs and good UPFs depending on their specific nutritional profile?
Certainly, the impact of consuming UPFs on human health is still not fully understood, which explains why most regulators have so far been reluctant to curtail their availability or warn against their harms.
What we do know is that these types of food now form a central part of the average diet, albeit with significant variations by country. A 2021 review of studies providing data on the level of UPF consumption found that the United States and the United Kingdom were the countries with the highest percent energy intake from UPFs (generally >50%), whereas Italy had the lowest levels (about 10%). More recently, research published in July found that UPFs account for almost two thirds of the daily energy intake of UK adolescents, according to analysis of food diaries kept from 2008 to 2019.
The debate over UPFs has filtered into the public’s consciousness, sparking concern over the risk to future health. A survey of 10,000 people from 17 European countries from the EIT Food Consumer Observatory, published in February 2024, found that a majority (67%) of European consumers do not like it when their foods contain ingredients they do not recognise, and 40% do not trust that UPFs are regulated well enough by authorities to ensure these foods are safe and healthy in the long term.
Weighing the risks
Regulators are coming under growing pressure to act, not only from members of the public but from health campaigners and scientists like van Tulleken. Should they choose to do so, they will need to weigh the risks of UPF consumption against the advantages of food processing, which has long played an important role in improving food safety and delivering other social benefits. Pasteurisation, for example, kills off harmful bacteria in products such as milk, while processing can improve the taste or texture of food and increase its shelf-life, making food more accessible or affordable and helping reduce waste.
There is currently no legal definition of a UPF, however most academic studies categorise foods according to the NOVA classification – a system of grades developed in Brazil that compares the degree of processing of food and drink products on a scale of one to four. It ranges from unprocessed or minimally processed foods like fruits and eggs in group one, to ultra-processed foods like cereals, biscuits, cakes and chicken nuggets in group four. These are distinguished from other foods both by the use of non-domestic, industrial processes like hydrogenation, extrusion and moulding, and by the fact the final product contains little if any intact food from group one.
One shorthand way for the public to decide whether something is a UPF is to consider whether it contains an ingredient they wouldn’t recognise from their own kitchen. UPFs are often associated with the use of food additives such as emulsifiers, stabilisers, gelling agents and thickeners that help to mix or thicken ingredients, and preservatives that are used to keep food safer for longer by slowing the growth of microorganisms.
Food additives have to pass a robust assessment to check they are safe for people to eat, including analysis of the toxicological profile of a particular additive, its concentration in particular foods, the range of foods in which it is used, and how much we might be exposed to it in our overall diets.
Yet the argument over the dangers of UPFs is less to do with harm caused by specific additives or foods and more concerned with dietary patterns and how this cocktail of substances interacts with our bodies when consumed over a sustained period of time.
Dividing lines
Van Tulleken set out his hypothesis in an interview with the New Scientist magazine in 2023 in which he explained: “The industrial processes involved in food manufacturing change its chemical and physical structure. They reduce food crops to their core constituents, such as high fructose corn syrup made from corn starch or hydrolysed vegetable protein from soya beans, which are then reformulated into substances that are highly palatable and calorific. These processes strip out fibre and micronutrients. Then ingredients are added that our bodies haven’t evolved to cope with, such as artificial flavourings and emulsifiers. We have evolved to eat naturally arranged matrices of different chemical constituents and when you separate them into their molecular components and chemically modify them, they seem to interact with the body in a very different way.”
The food industry has pushed back against the notion that UPFs are intrinsically bad amid criticism that the NOVA system is too simplistic in classifying products such as wholemeal bread alongside those like chocolate biscuits and doughnuts. In April 2023, I attended a briefing organised by the trade body, FoodDrinkEurope, which questioned whether the concept of UPFs places too much emphasis on the processing of foods and not enough on the ingredients that go into making them. Gert Meijer, Nestlé’s Deputy Head for corporate regulatory and scientific affairs, summed up the industry line of defence when he described a, “mix up between what we would say is formulation and actual processing”. He added: “There is no proven relationship between the degree of processing and the healthiness of a food product.”
Although evidence does exist (and is growing) to suggest a relationship between UPF consumption and negative health outcomes, proving causality has indeed remained out of reach. The British Nutrition Foundation (BNF), which is part funded by food companies, reflected this fact in a position statement in which it argued against blanket dietary advice to avoid UPFs, some of which, like wholemeal bread and lower sugar wholegrain breakfast cereals, can contribute to an affordable, healthy, balanced diet. The BNF noted how current evidence is largely based on observational studies that, by design, cannot demonstrate cause and effect, and called for further studies to be undertaken.
Evidence base
Evidence showing a correlation between UPF consumption and poor health outcomes includes research into UK adults published in 2020 that found a diet high in UPFs is associated with a clinically important increased risk of type 2 diabetes. The findings prompted the researchers to conclude that, “identifying and implementing effective public health actions to reduce UPF consumption in the UK and globally are urgently required”.
Another study from 2023 found that diets high in UPFs could be linked to an increased risk of developing and dying from cancer. Researchers from Imperial College London’s School of Public Health found that higher consumption of UPFs was associated with a greater risk of developing cancer overall, and specifically with ovarian and brain cancers.
A more recent addition to the evidence base came courtesy of research from the University of Central London (UCL), published in July, which found that UPFs contain more calories, fat, saturated fat, sugar and salt than minimally-processed foods – but that not all UPFs are unhealthy. Researchers compared data on the level of processing in commonly eaten foods to the nutritional information found on front-of-pack labels and found that UPFs (as classified under NOVA) had worse nutritional scores, with greater levels of energy, fat, saturated fat, sugar and salt than minimally processed foods. Yet the results also indicated that not all UPFs are unhealthy based on their nutrient profile with products such as meat-free mince scoring positively under traffic light label systems, despite being categorised as ultra-processed. “At the moment, things aren’t so clear cut as to say all UPFs are bad and there is a risk of confusing people about what is healthy to eat,” said Dr Adrian Brown, a specialist dietitian from UCL Division of Medicine.
Regulatory waiting game
The volume of noise around UPFs has been sufficient for regulators in some countries to tentatively intervene. In May, the UK’s Food Standards Agency (FSA) published advice for consumers in which it stated that, while there is a correlation between poorer health outcomes and diets that are high in UPFs, “we still don’t know whether it is because these foods are unhealthy because of how they are made, or if it’s because a large majority of processed foods are high in calories, saturated fat, salt and sugar”.
The FSA also pointed to an evidence review by the UK Government’s expert scientific committee, the Scientific Advisory Committee on Nutrition (SACN), which concluded that more research is needed before it could draw any firm conclusions about whether UPFs cause poor health, despite finding associations between increased consumption of UPFs and an increased risk of health issues such as obesity, chronic diseases like type 2 diabetes, and depression.
In Europe, meanwhile, there is no sign that regulators are considering targeting UPFs as a distinct food group for reduction or avoidance, with the European Food Safety Authority (EFSA) having remained largely silent on the issue.
Beyond Europe, however, some countries are taking decisive action to guard against excessive consumption of UPFs. Brazil’s dietary guidelines emphasise the benefits of diets based on a variety of natural or minimally processed foods, mostly plants, and freshly prepared meals as well as the multiple negative effects of ready-to-consume ultra-processed food and drink products. Brazil and Chile have also introduced warning labels for foods high in salt, sugar and fat, a group dominated by ultra-processed products which tend to have a poorer nutritional profile than unprocessed foods.
Some campaigners would have European countries follow suit, albeit any such policies would be fiercely resisted by parts of the food industry. More likely is that regulators will continue to watch with interest from the sidelines until research proves conclusively of the harm to health from eating ultra-processed foods.
