July 20, 2022

expert reaction to study looking at the ultra-processed food content in school meals and packed lunches in the UK

A study published in Nutrients looks at the ultra-processed food (UPF) content of school meals and packed lunches in the UK.

Dr Annette Creedon, Nutrition Scientist and Manager, British Nutrition Foundation, said:

“The term ‘ultra-processed foods’ is increasingly used in research on diet and health, with some findings suggesting eating some of these foods may be associated with risk of disease.  However, the majority of these studies are observational, and so can’t establish that eating more ‘ultra-processed foods’ actually causes the disease.  It may be that the people in these studies have poor lifestyle and eating habits overall.

“The term ‘ultra-processed foods’ usually refers to foods and drinks produced in factories that can contain additives such as colours, flavours, emulsifiers or preservatives, or ingredients we do not typically find at home.  The NOVA definition of ‘ultra-processed foods’ that is used to categorise foods within this study by Parnham and colleagues is based purely on the level of processing – not on the nutrient content of the food.  ‘Ultra-processed foods’ include an enormous range of products, such as confectionary, fried snacks, cakes and sugary drinks, which most of us know are foods we should be eating less of.  But the definition also includes foods that can be part of a healthy, balanced diet such as wholemeal sliced bread, lower sugar yogurts, wholegrain breakfast cereals and baked beans.  Hence, it is important to consider the nutritional contribution these processed foods may be making to the diet, rather than treating them all as a single group of unhealthy foods.

“This may influence the findings of Parnham and colleagues, who found that the composition of packed lunches by primary and secondary schoolchildren had high levels of ‘ultra-processed foods’.  To understand nutritional intake, it is important to consider the specific foods consumed within each meal type (school meal or packed lunch) rather than considering the foods based on broad classifications of ‘minimally-processed foods’ and ‘ultra-processed foods’.  Processing foods can help to make some relatively healthy foods more accessible and affordable, and this affordability aspect may also explain the observed socioeconomic gradient of ‘ultra-processed foods’ in packed lunches.  It is important that we all make healthier food choices, and a healthy, balanced diet (and packed lunch) can be achieved without having to exclude processed foods from the diet completely. “

Dr Duane Mellor, Registered Dietitian and Senior Teaching Fellow, Aston Medical School, Aston University, said:

“This study highlights some of the challenges with school meal provision.  It suggests that nearly 2/3s of the calories in school meals come from ultra processed foods which tend to be high in fat, salt and sugar.  However over 30% of the children and young people in the study did not report what they had to eat at lunchtime.  It also does not look at what food was offered or why the food eaten was chosen.

“Children and young people need to be offered healthy school food which is affordable and enjoyable.  Often the less healthy options are attractive and so chosen ahead of what might be healthier foods.  With concerns about the cost of living and concerns about waste, both caterers and those buying the food are likely to take less risks and therefore not chose new or unfamiliar foods which might be healthier.  This study highlights that we need to change how we treat food in schools to be part of the education and learning for the students.  Supporting trying new foods, developing cooking skills and properly funding school foods so reducing ultra processed foods is a realistic option.”

Prof Gunter Kuhnle, Professor of Nutrition and Food Science, University of Reading, said:

“Ultra-processed food (UPF) is a term that has become very common but is very vaguely defined.  For example, the authors class chips as “ultra-processed”, even though the only processes involved are cutting and deep-frying potatoes.  In contrast, cheese and bread, which involve many more processing steps, are considered only “processed”.

“There is an ongoing discussion about the health-effect of ultra-processed foods.  This is confounded not only by an ambiguous definition, but also the fact that ultra-processed foods are often cheaper, for example due to longer shelf-life or better use of resources.  They are therefore often consumed by people who have an overall higher risk of poor health.  There are also data that show that many ultra-processed foods can lead to overconsumption, but this does not apply to all such foods.

“The findings of this study are not surprising: most people consume “industrially manufactured bread” and sandwiches as packed lunches are not uncommon.  However, there is no evidence to suggest that such bread has an adverse effect on health.  Unfortunately there were no data on the nutrient profile, which would have made a comparison much easier.  Not all UPFs are high in fat, salt or sugar, or have an altered food structure.

“Food processing has an important place in our food system.  It keeps our food safe and secure and can help to reduce spoilage and food waste.  Reformulation of foods – which would lead to a categorisation as “ultra processed” – can be an important method to improve overall dietary intake: the reduction of salt and sugar in the UK diet are a prime example for this.  Industrial manufactured bread – a staple food for most people – can be reformulated to increase the fibre content.

“Demonising food is never a good idea – ultra processed foods can play an important role to ensure an affordable supply of healthy food.”

‘The ultra-processed food content of school meals and packed lunches in the United Kingdom’ by Jennie C Parnham et al. was published in Nutrients at 03:00 UK time on Wednesday 20 July 2022.

Declared interests

Dr Annette Creedon: “Funding to support the British Nutrition Foundation’s charitable aims and objectives comes from a range of sources including membership, donations and project grants from food producers and manufacturers, retailers and food service companies, contracts with government departments; conferences, publications and training; overseas projects; funding from grant providing bodies, trusts and other charities.  Further information about the British Nutrition Foundation’s activities and funding can be found at http://www.nutrition.org.uk/aboutbnf/.”

Dr Duane Mellor: “I have no conflicts of interest.”

Prof Gunter Kuhnle: “Some of my research has been funded by Mars, Inc. and I have co-authored a review on ultra-processed food.”