British primary and secondary schoolchildren are getting the majority of their lunchtime calories from ‘ultra-processed’ foods, according to a study led by researchers at Imperial College London and published today in the journal Nutrients.
The analysis, which looked at the content of school lunches of more than 3,000 children between 2008-2017, finds that 64% of the calories in meals provided by the school come from ultra-processed foods, contributing to the consumption of high levels of processed foods and increasing the risk of childhood obesity. Ultra-processed bread, snacks, puddings and sugary drinks were among the biggest contributors, and on the whole packed lunches contained more calories from highly processed foods, compared to school meals.
According to the researchers, publicly funded school meals (i.e. free school meals and those that children buy in school) are a vital mechanism to deliver healthy food to children, especially those from families with low incomes. They explain the findings highlight a key opportunity for policy makers and educators to ‘level the playing field’ by improving the nutritional quality of school lunches. They argue that urgent policy changes are needed to cap the amount processed foods school lunches contain and to increase access to free school meals, which could help to boost the diets and health of Britain’s children.
Dr Jennie Parnham, from the School of Public Health at Imperial College London and first author on the paper, said: “This is the first study to look at the extent of ultra-processed food content in school lunches for children of all ages. We need to view these findings as a call to action to invest in policies that can promote healthy eating. Owing to the current cost of living crisis, school meals should be a way for all children to access a low-cost nutritious meal. Yet, our research suggests this is not currently the case.”
She continued: “Ultra-processed foods are often cheap, readily available, and heavily marketed – often as healthy options. But these foods are also generally higher in salt, fat, sugar, and other additives, and linked with a range of poor health outcomes, so it’s important that people are aware of the health risks of children consuming them in high levels at school.
“As food prices continue to rise in the UK and globally, accessing affordable, healthy food will become more challenging for many more people. School meals should offer children from all backgrounds access to a healthy and minimally processed meal, yet they are currently failing to meet their potential.”
Ultra-processed foods (UPFs) are items which are heavily processed during their making: such as frozen pizzas, fizzy or milk-based drinks, mass-produced packaged bread and many ready meals. Previous research has linked regular consumption of them with obesity and increased long-term risk of health conditions like Type 2 diabetes, cardiovascular disease and cancer.
Previous research by the team reported the scale of UPFs being consumed by children in the UK, which is the highest in Europe. The work also highlighted that eating patterns established in childhood extend into adulthood, potentially setting children on a lifelong trajectory for obesity and a range of negative physical and mental health outcomes.
In the latest study, the team looked at the diets of more than 3,300 children in primary and secondary school, collected through the National Diet and Nutrition survey . The aim was to examine the proportion of UPFs in packed lunches (food brought from home) and school meals (which includes lunches provided by the school (free school meals) or bought by students at the school canteen).
The analysis included data from 1,895 primary school children (aged 4-11) and 1,408 secondary school children (aged 11-18), looking at food groups making up the total calorie count, as well as the proportion of total food intake of the meal (in grams).
Overall, around 75% of calories across all types of school lunches came from UPFs – with 82% of calories from UPFs in packed lunches, compared with 64% in school meals – across all ages.
However, within school meals the study found that secondary schoolchildren had higher levels of UPFs (70% of calories) compared to primary schoolchildren (61% of calories). Secondary school meals contained a higher proportion of calories from fast food items, puddings and desserts.
In general, children from lower-income backgrounds were more likely to have higher levels of UPF on their plates (77% of calories) than children from higher-income backgrounds (71% of calories).
In primary school, almost half of the calories in packed lunches came from ultra-processed bread and snacks, compared to just 13% of calories of school meals. Packed lunches also tended to have fewer calories from minimally processed fruit and veg, meat and dairy, and starch (such as pasta or potatoes), compared to school meals.
One of the largest UPF contributors, as a proportion of grams of food intake, came from ultra-processed drinks – such as fizzy drinks, fruit juice, or yogurt drinks. According to the team, one of the easiest and most cost-effective opportunities to improve the nutritional value of school lunches would be to swap these high calorie, ultra-processed drinks for water.
While the work is the first to bring together both primary and secondary school settings, the researchers highlight the limitation that secondary schoolchildren self-reported their dietary data while primary schoolchildren did not, but this mostly likely means that the scale of UPFs being consumed by secondary schoolchildren is under-estimated.
Dr Eszter Vamos, from Imperial’s School of Public Health, added: “With the rising cost of living, many families are struggling to access healthy foods, and school meals might be the only opportunity for many children to have a healthy regular main meal. School meals are critically important in making sure that every child has access to an affordable nutritious meal.
“Children in England consume very high levels of ultra-processed foods, and it is worrying that meals consumed at school contribute to this. Our findings call for urgent policy changes to improve the accessibility and quality of school meals as this could shape children’s overall diets considerably with important consequences for their current and future health.”
This study is funded by the National Institute for Health and Care Research (NIHR), through the NIHR School for Public Health Research.
About Imperial College London
Imperial College London is one of the world’s leading universities. The College’s 20,000 students and 8,000 staff are working to solve the biggest challenges in science, medicine, engineering and business.
Imperial is University of the Year 2022 in the Times and Sunday Times Good University Guide. It is the world’s fifth most international university, according to Times Higher Education, with academic ties to more than 150 countries. Reuters named the College as the UK’s most innovative university because of its exceptional entrepreneurial culture and ties to industry.
Imperial has a greater proportion of world-leading research than any other UK university, according to the Research Excellence Framework (REF). Imperial ranks first in the UK for research outputs, first in the UK for research environment, and first for research impact among Russell Group universities.
About the National Institute for Health and Care Research (NIHR)
The mission of the National Institute for Health and Care Research (NIHR) is to improve the health and wealth of the nation through research. We do this by:
Funding high quality, timely research that benefits the NHS, public health and social care;
Investing in world-class expertise, facilities and a skilled delivery workforce to translate discoveries into improved treatments and services;
Partnering with patients, service users, carers and communities, improving the relevance, quality and impact of our research;
Attracting, training and supporting the best researchers to tackle complex health and social care challenges;
Collaborating with other public funders, charities and industry to help shape a cohesive and globally competitive research system;
Funding applied global health research and training to meet the needs of the poorest people in low and middle income countries.
NIHR is funded by the Department of Health and Social Care. Its work in low and middle income countries is principally funded through UK Aid from the UK government.