Impact of ultra-processed food on children’s health

On 24 October 2023, the House of Lords is due to consider a question for short debate, tabled by Baroness Jenkin of Kennington (Conservative), to ask the government what assessment it has made of the impact of ultra-processed foods on children’s health.

1. What are ultra-processed foods?

The term “ultra-processed foods” (UPFs) derives from the NOVA food classification system, which was developed by researchers at the University of Sao Paulo, Brazil, in 2010. NOVA classifies commercially available foods and drinks into four groups based on their preparation method and the degree of processing they have undergone. They are as follows:

1. Unprocessed and minimally processed foods. Unprocessed foods are described as the “edible parts of plants” (for example, fruits, leaves, roots, seeds, stems and tubers) or “from animals” (such as muscle, offal, eggs and milk), and also “fungi, algae and water, after separation from nature”. Minimally processed foods is used to describe unprocessed foods that have been altered by industrial processes, such as chilling, freezing and powdering. For example, frozen vegetables, herbs and spices.
2. Processed culinary ingredients. These are defined as “substances obtained directly from group one [unprocessed and minimally processed] foods or from nature by industrial processes”, such as extracting, pressing and refining. Examples of processed culinary ingredients include honey and vegetable oils.
3. Processed foods. This describes products made by adding oil, salt, sugar or other processed culinary ingredients to unprocessed and minimally processed foods, using preservation methods. For example, bottled or canned vegetables in brine, salted nuts, and smoked fish and meats.
4. UPFs. This is defined as “formulations of ingredients, mostly of exclusive industrial use, typically created by [a] series of industrial techniques and processes”. UPFs include baby formula, sweetened breakfast cereals, carbonated soft drinks, mass-produced packaged breads, margarine and other spreads, and reconstituted meat products.

The production of UPFs involves multiple stages. It starts with the breakdown of whole foods into components like sugars, oils, fats, proteins, starches and dietary fibre. These components are frequently derived from a select group of high-yield plant sources (such as beet, corn, soy, sugarcane or wheat) and from the processing of animal carcasses, typically sourced from intensive animal farming.

2. What are the potential impacts of ultra-processed foods on children’s health?

2.1 Report by the First Steps Nutrition Trust

Concerns have been raised about the potential impact of UPFs on the health and wellbeing of children. The First Steps Nutrition Trust (FSNT), a public health nutrition charity, has reported several negative health and wellbeing outcomes associated with UPF consumption:

• Dietary nutrient imbalances. Referring to a 2022 article by Carlos Monteiro and Gyorgy Scrinis in the journal Nature Food (£), FSNT argued that nationally representative studies conducted in 13 countries, including the UK, found a “strong inverse correlation” between the consumption of UPFs and the nutritional quality of diets. The FSNT contended that although there were “multiple drivers” of poor diet quality among infants and young children, the extent to which UPF “dominate[d]” their diets is “now recognised as a significant factor in nutrient deficiencies at population level, including in the UK, both in terms of nutrients to promote and limit”.
• Increases to energy intake. Discussing the findings of a 2019 randomised controlled trial involving US adults detailed in the journal Cell Metabolism, the FSNT stated that it had provided “important” evidence of a causal connection between the consumption of UPFs and increased calorie intake, leading to subsequent weight gain. Despite both diets being matched in fibre, energy, macronutrients, sodium and sugar (though not texture, or the energy density of the meals), subjects were instructed to consume as much or as little as they wanted. The FSNT said that the results revealed that those eating a UPF-rich diet consumed more calories, largely due to larger portion sizes, resulting in increased fat and carbohydrate intake and subsequent weight and body fat gain. Furthermore, the FSNT stated that the “convenience, hyper-palatability, and intensive marketing” of UPFs could lead to overconsumption, particularly among infants and young children.
• Disruptions to the development of taste preferences and dietary habits. The FSNT argued that the foods “disrupt taste preferences, displace minimally and unprocessed foods, and encourage unnecessary snacking”. This contributed to “nutritionally imbalanced diets and a food culture dominated by UPFs”. The FSNT also stated that UPF consumption in early childhood was a “specific cause for concern” as it could lead to children preferring these foods, which, in turn, could lead to dietary patterns dominated by UPFs into adulthood.
• Risk of affecting the “optimal development” of the gut microbiota. The FSNT noted that UPFs may contribute to long-term diseases by changing the gut microbiota and “encouraging low-grade inflammation”. It argued this could favour the development of cancer, type 2 diabetes and cardiovascular disease. It also said that the impact of UPF-rich diets on the gut microbiota was of “particular importance in infancy”, as this was the “crucial period in the development of the immune system”.
• Consumption of harmful additives and contaminants. The FSNT stated that there had been “little scrutiny” of the health impacts of these additives at the population level, especially among infants and young children. Despite this, the charity noted that a 2022 study among adults in France had reported associations between certain additives, like emulsifiers and artificial sweeteners, and cancer risk.

2.2 Findings by the Scientific Advisory Committee on Nutrition

In June 2022, the UK’s Scientific Advisory Committee on Nutrition (SACN) considered UPFs at a horizon-scanning meeting. Members of the SACN concluded that it would be timely to consider the issue since there was increasing debate about the health implications of food processing. In autumn 2022 the Office for Health Improvement and Disparities at the Department of Health and Social Care asked the committee to expedite this work.

The SACN agreed on the terms of reference for a review into UPFs in November 2022. The terms of reference were to issue a position statement on food processing and health, which would include:

• evaluating existing classifications of processed foods (including UPFs and the NOVA classification)
• evaluating the suitability of methods to apply food processing definitions “as a dietary exposure”
• considering the availability and quality of evidence associating different forms or levels of food processing with health outcomes

Additionally, SACN outlined its intention to scope any future work on this issue.

The SACN published the findings of its review in a summary report in July 2023. It noted that existing scoping reviews had consistently reported that increased consumption of UPFs was associated with higher risks of adverse health outcomes. However, the committee argued that there were “uncertainties around the quality of evidence available”, noting that studies were “almost exclusively observational” and may not “adequately account” for confounding factors such as body mass index, energy intake, smoking and socioeconomic status.

Highlighting the limitations identified in the available evidence, the committee recommended that further research be undertaken in several areas, including in assessing and developing a UPFs classification system that can “reliably be applied” to estimate processed food consumption in the UK.

3. Are all ultra-processed foods potentially unhealthy?

Whilst UPFs are generally considered unhealthy, some commentators have argued that some UPFs can be healthy.

In an article on the British Heart Foundation website in August 2023, Victoria Taylor, the charity’s senior dietician, argued that “it’s also important to remember that not all UPFs are equal”. She warned that “one of the criticisms of the NOVA method of categorising foods” is that foods such as baked beans and wholemeal breads “sit alongside less nutritious ultra-processed foods”.

Speaking to the Times (£) in September 2023, the head of the nutritional epidemiology group at the University of Leeds, Professor Janet Cade, highlighted that the nutritional value of a vegetable can change “very little” between its original state and going through various stages of processing. Speaking to the Telegraph (£) in the same month, she also argued that if UPFs were removed from people’s diets then “this would require a huge change in the food supply”. She said this could be “really unachievable for most people” and could result in “further stigmatisation and guilt in those who rely on processed food, promoting further inequalities in disadvantaged groups”.

In the same article, the chief scientific adviser to the Food Standards Agency, Professor Robin May, warned against stopping people from buying UPFs. He argued that many components of UPFs were there for “safety reasons”. For example, he said additives that “reduce the growth of bacteria or fungi have a really critical role in protecting consumers and extending the life of a product”.

4. What is the prevalence of ultra-processed foods in the UK?

4.1 Marketing

In 2021, researchers from the Joint Research Centre at the European Commission conducted a study on the NOVA classification of foods and drinks marketed in European markets (including the UK) for infants and young children in the UK. Correspondence between the researchers and the FSNT revealed that although just 29.2 percent of products were categorised as UPFs, the proportion increased for baby snacks (48 percent), baby cereals (53 percent) and baby biscuits and rusks (73 percent). The following chart details findings from the study.

Chart 1: NOVA classification of foods and drinks marketed for infants and young children, rounded, UK, 2021

4.2 Consumption

In a report examining the impact of such foods on the diets of infants and young children in the UK, the charity detailed the findings of previous studies into the consumption of UPF on children:

• According to a 2022 survey of parents whose youngest child was up to six months old, between a “third and a quarter purchased commercial baby meals, finger foods and/or baby drinks, and more than a third of babies were given such products at least once a day”. It then outlined estimates that “up to about a half of baby meals, close to three quarters of finger foods and one in five baby drinks may be UPF”.
• Despite public health recommendations stating that baby formula was “unnecessary” for children aged over one year old, a survey of 800 parents with one-year-old children found that 49 percent of them had bought commercial milk formula and 55 percent of the children were given formula at least once a day.
• Data from the Gemini twin cohort study, which included 2,336 children born in the UK in 2007, was recently examined to evaluate the consumption of UPFs at 21 months of age. It found that UPFs contributed to 47 percent of their average energy intake. Although it acknowledged the age of the study, the FSNT stressed that these food types remained common and that, according to a 2019 survey, many foods marketed at children (for example, using cartoon characters on packaging) were found to be “unhealthy”.

Additionally, data from the UK National Diet and Nutrition Survey from 2008 to 2014 found that UPFs accounted for nearly two-thirds (61 percent) of the total energy intake of UK children aged two to five at that time. This was higher than any of the other six countries studied, including the US and Australia. The findings are detailed in the chart below.

Chart 2: Contribution of UPFs and the other NOVA food groups to total mean energy intake in two- to five-year-olds in the UK and six other countries, 2022

In a separate study in 2022, researchers at Imperial College London found that British primary and secondary school children were getting the majority of their lunchtime calories from UPFs. The study, which examined the content of school lunches of more than 3,000 children between 2008 and 2017, found that 64 percent of the calories in meals provided by the school came from UPFs.

5. Recent government policy on ultra-processed foods

The government’s recent policy on UPFs reflects the SACN’s conclusions that the observed associations between these foods and health are concerning, but that the underlying causes are not yet fully understood.

In a House of Commons debate on UPF in June 2023, Neil O’Brien, parliamentary under secretary at the Department for Health and Social Care, stated that there was “no universally agreed definition of ultra-processed food; nor is there an evidenced position”. In contrast, Mr O’Brien said that there were definitions of products that are high in fat, salt and sugar (HFSS), and that “is the basis on which we [the government] regulate and control those foods”. He also outlined that the government’s existing policies “support[ed] less consumption of many of the foods that would be classified as ultra-processed because they are high in fat, salt and sugar” and that it would “not hesitate to take action if the evidence suggests that it is needed”.

Following the publication of the SACN’s findings into UPFs, the government was asked in the House of Lords in July 2023 what assessment it had made of the latest research into the effects of UPF on the mental and physical health of children and adults and whether it planned to introduce further restrictions on such foods. Responding, Lord Markham, parliamentary under secretary of state at the Department of Health and Social Care, highlighted that the SACN “did not find evidence for a causal link between UPFs and mental and physical health”. Lord Markham also said it was “unclear” whether UPFs were “inherently unhealthy”, or whether the issue was instead that such foods were “typically high in calories, saturated fat, salt, and sugar”. Therefore, he reaffirmed that the government’s priority was “continued action” to reduce the consumption of foods high in calories, salt, sugar and saturated fat.

5.1 Recent government measures aimed at reducing salt, saturated fats and sugar consumption

In recent years, successive governments have introduced measures aimed at reducing the consumption of foods high in salt, saturated fats and sugar. They include:

• Advertising restrictions. The Health and Care Act 2022 introduced new advertising restrictions for HFSS foods in the UK. The restrictions included a 9pm watershed for HFSS food advertisements on television and UK on-demand programmes, and a prohibition on paid-for advertising of unhealthy food and drink products online. The restrictions were originally due to come into force in January 2023 but were delayed by the government. Following consultation, the restrictions are now due to come into force on 1 October 2025.
• Calorie labelling. In July 2021 the government laid the Calorie Labelling (Out of Home Sector) (England) Regulations 2021. The regulations entered into force on 6 April 2022. The regulations imposed a legal requirement on businesses in England with more than 250 employees, including fast food outlets, restaurants and supermarkets, to display calorie information for non-prepacked food and drinks.
• Reduction and reformulation voluntary programme. First launched in 2016, the sugar, salt and calorie reduction and reformulation programme is a series of voluntary initiatives designed to encourage the food industry to reduce the levels of sugar, salt and calories in processed foods and drinks. The programme is overseen by the Office for Health Improvement and Disparities.
• Soft drinks industry levy. In the 2016 budget David Cameron’s government announced a soft drinks industry levy targeted at producers and importers of soft drinks that contained more than 5g of sugar per 100ml. The levy was implemented through the Finance Act 2017 and came into effect in April 2018. The two current rates of the levy are the standard rate (18p per litre), applied to drinks with sugar content between 5g and up to (but not including) 8g per 100ml, and the higher rate (24p per litre), applied to drinks with sugar content equal to or greater than 8g per 100ml.

6. Read more

• House of Commons, ‘Written question: Schools—processed food (198875)’, 19 September 2023
• House of Commons, ‘Written question: Processed food—consumption (198873)’, 13 September 2023
• Oral question on ‘Children’s health: Sugar’, HL Hansard, 12 September 2023, cols 781–4
• House of Commons Library, ‘Obesity policy in England’, 20 June 2023

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Cover image by Aline Ponce on Pixabay.