Appetite for change: Do we need to regulate ultra-processed foods?

By the time the term ‘ultra-processed food’ had established itself in the lexicon of nutritional science, the products which it seeks to describe had long since become a mainstay of our diets. Beginning in the late 1970s and increasing throughout the 1980s, foodstuffs containing artificial additives and preservatives began to make up an increasing proportion of the calories we consume. However, it wasn’t until 2009 that the Brazilian scientist Carlos Monteiro coined the term alongside the creation of a new classification system (Nova) which groups foods based on their level of processing.

In the years since, concern over the consumption of UPFs has gone mainstream alongside a growing understanding of the importance of gut health and the gut microbiome, essentially an ecosystem of microorganisms in our intestines which scientists now believe have a role not only in digestion and metabolism but in everything from mental health and cognition to the pathologies of major diseases such as cancer and Alzheimer’s.

Last year a review published in The Lancet concluded that foods which have undergone a high level of processing are a major public health threat worldwide, with researchers calling for increased regulation – such as health warnings and higher taxes – to help change consumer behaviour in favour of more nutritious alternatives. In reviewing the available evidence, the scientists said the rise of UPFs was responsible for deteriorating diets, with better education about the health impacts insufficient in the face of the huge influence exerted by multinational food and drink companies. In an accompanying editorial, the medical journal warned that UPFs are “damaging public health, fuelling chronic diseases worldwide, and deepening health inequalities” as well as being emblematic of a food system which prioritises corporate profit over public health.

Monteiro, the review’s author, says: “This change in what people eat is fuelled by powerful global corporations who generate huge profits by prioritising ultra-processed products, supported by extensive marketing and political lobbying to stop effective public health policies to support healthy eating.”

The public health challenges associated with Scotland’s poor diet are nothing new. More than one in five children starting primary school are at risk of being overweight or obese, while around two-thirds of adults are overweight. It is estimated that by 2040 there will be an additional 118,000 female and 36,000 male cases of obesity. And while the causes remain unclear, there has been a worrying rise in the number of younger people developing bowel cancer in Scotland, with the number of under-50s being diagnosed with the disease rising by roughly 50 per cent in the past decade (from six to nine cases per 100,000).

Under Monteiro’s Nova classification system, foods are grouped into four categories, with UPFs such as ready meals, fizzy drinks, biscuits and crisps in category four. However, the system is far from straightforward, with many foodstuffs found in a balanced diet, such as cheese, low-fat yoghurt and sliced wholemeal bread, considered to be either processed or ultra-processed. There is also a difficulty in understanding exactly what is meant by something being ultra-processed. One rule of thumb is that if a food contains ingredients not usually found in a kitchen cupboard, such as emulsifiers, preservatives, additives, dyes and sweeteners, then it can probably be considered to be ultra-processed. But Food Standards Scotland, the public body charged with protecting consumers, concluded in 2024 that while there was evidence of a link between UPFs and health, it was not strong enough to warrant a change in either dietary advice or policy direction. Instead, the body advises the public to follow a diet low in saturated fat, sugar and salt, all of which can often be found in high levels in foods which have undergone processing. 

According to a study published in the British Medical Journal (BMJ), UPFs make up 56.8 per cent of the total energy intake in the UK diet – the highest level in Europe. Involving more than 9,000 participants over the age of 18 months, the study also found that UPFs account for the consumption of 64.7 per cent of so-called free sugars (sugar added to food by the manufacturer). 

“Although more research is clearly warranted, the need for further evidence should not delay public health action,” Monteiro and his colleagues say in their review. “Policies that promote and protect dietary patterns based on a variety of whole foods and their preparation as dishes and meals, and that discourage the production and consumption of UPFs, cannot be postponed. These policies are particularly urgent in countries where the ultra-processed dietary pattern does not yet prevail. These strategies should complement – not replace – existing policies and actions designed to reduce consumption of products high in added fats, sugar, or salt, and excessive red meat intake, as such consumption is harmful regardless of the level of processing.”

But despite the growing concern of some scientists, there has been no rush to regulation in the UK. In 2023, the Scientific Advisory Committee on Nutrition (SACN), which advises both the UK and Scottish governments, concluded that while there was a “concerning” link between UPFs and ill-health, it was unclear from the available evidence whether these foods are inherently unhealthy due to the way they are processed or due to the fact they usually contain high levels of saturated fat, salt and/or sugar. In an update published last year amid further scientific research into UPFs, the SACN said there remained “significant limitations” in the evidence base, but nevertheless it recommended that the government consider health messaging around processing as well as compelling the food industry to make processing data publicly available. It also called for the monitoring of the consumption of individual additives such as emulsifiers and non-sugar sweeteners (NSS).

“There’s a lot of hype around ultra-processed food but actually the evidence is limited,” says Alex Johnstone, a professor at the University of Aberdeen’s Rowett Institute. “The UK Government hasn’t given any advice on altering diets to take account of ultra-processed food. I think we need a lot more information and individuals would find it very hard to limit ultra-processed food or even understand what they are – there are no mechanisms in place for consumers to get that guidance.” 

Johnstone believes that issuing explicit guidance about UPFs could be counter-productive, causing some consumers to switch to alternatives which are not classified as ultra-processed but could be less nutritious than what they were eating before. She says that until the link between ultra-processed foods (UPFs) and poor health is better understood, the focus of official advice should remain on avoiding foods which contain high levels of fat, sugar and salt.

One obvious consideration with UPFs is that they tend to be cheap. While the rate of food price inflation has fallen back from the historic highs seen after the pandemic, the cost of an average shop continues to increase, putting more pressure on household budgets. 

“You don’t want unintended health consequences from public health policy decisions,” Johnstone says. “We know that for some people in the population, ultra-processed food is a high proportion of their weekly shopping basket. If we’re going to make changes to the guidance, we need to think about what these kinds of food are going to be substituted for and how that impacts on the cost of food, the cost of a healthy food basket, and how we’re going to feed families.” 

Scotland’s first Good Food Nation Plan, which was published in December and seeks to “encourage the creation of food environments that enable more people to eat healthy and nutritious foods”, makes no mention of ultra-processed food. However, in response to a petition from a member of the public calling for UPFs to be banned in school meals, the Scottish Government said a ban based on the Nova classification scheme would be “challenging” and would lead to the exclusion of products fortified with vitamins and minerals. 

The debate around processed foods takes place against the background of an obesity epidemic in the UK. Campaigners have accused successive UK governments of balking at increased regulation due to the lobbying power of the food industry. Nevertheless, there have been interventions, notably the Soft Drinks Industry Levy (SDIL), the so-called sugar tax which was introduced in 2018 and has been shown to reduce the amount of sugar consumed by both adults and children. The policy was extended last year to include sugary milk-based drinks. 

Meanwhile, a ban of junk food advertising on TV and online came into force earlier this month. Adverts for food and drinks high in fat, salt and sugar now cannot be shown on TV before 9pm and at any time online. The ban applies to foods including soft drinks, sweet, pizzas and ice creams, among the biggest drivers of childhood obesity. The ban was introduced as new research showed those who come off weight-loss injections such as Mounjaro or Wegovy can regain their lost weight up to four times faster than those who have been following a conventional diet plan, suggesting they may not be the panacea many had hoped for. Data published in the BMJ said those who shed a fifth of their body weight while using the jabs could return to their pre-treatment weight within 18 months. 

Johnstone urges caution at suggestions addressing the amount of ultra-processed food in people’s diets could impact obesity levels. “The last thing we want is to stigmatise or scare people about the food they are eating. If there’s good evidence going forward that it’s the processing that has a negative effect on health, then the government might potentially take action to limit those types of food but from a nutrition point of view, what I want to see is a food environment that supports consumers making healthy choices.”