A major spike in child obesity levels during the pandemic could cost the UK over £8 billion, according to a study involving Imperial researchers.

Rates of obesity have been steadily increasing over the past decade or so among children in the UK; but the study found a sharp increase between 2019/20 and 2020/21 in reception pupils (aged 4-5 years) and year 6 children (aged 10-11).

While many reception pupils returned to healthier, pre-pandemic weights, obesity levels remained stubbornly high among the older, year six pupils.

This equates to an extra 56,000 children living with obesity as a result of the pandemic – incurring additional lifelong healthcare costs of £800 million, with a cost to society of £8.7 billion.

The study is published in the journal PLOS ONE and is led by the National Institute for Health and Care Research (NIHR) Southampton Biomedical Research Centre (BRC) in collaboration with researchers from the NIHR Imperial BRC, Imperial College London and the University of Southampton.

Study co-author, Imperial’s Professor Neena Modi (School of Public Health), commented: “Obesity rates disproportionately affect children living in deprived communities – and the gap between the most and least deprived groups has widened over the past ten years.

“We need targeted interventions to bridge this alarming divide especially in the under fives where our study shows overweight and obesity can be reversed most readily. This will help ensure every child has an equal chance to grow up healthy.”

Pandemic effects

Obesity increases the risk of many health diseases. These include type 2 diabetes, heart disease and some types of cancer. It also has an important effect on quality of life and mental health.

"The surge in childhood obesity during the pandemic illustrates its profound impact on children’s development." Professor Keith Godfrey

This study used data drawn from the National Childhood Measurement Programme (NCMP) to calculate the increase in childhood obesity rates among children. The report measures the BMI of children in reception (age 4-5) and year six (age 10-11) each year.

The analysis showed that childhood obesity levels rocketed between 2019-20 and 2020-21.

Experts put this down to a change in young people’s eating habits and activity levels. During this period most children were schooled from home. Organised sports and recreational activities were largely unavailable and there were effects on children’s sleeping schedules and screen time. 

By 2022, NCMP data shows the number of four- and five-year-olds living with obesity returned to pre-pandemic levels. However, overweight and obesity prevalence in children aged ten and eleven remained higher than expected, representing almost 56,000 extra children.

Costs of obesity

In this study, researchers projected the impact of child BMI trends on adult health measures to estimate costs to society.

They found that the increase in overweight and obesity prevalence in ten- and eleven-year-olds alone could cost the NHS £800 million. The cost to wider society could be at least £8.7 billion. This total includes costs relating to reduced productivity and quality of life.

Professor Keith Godfrey from the NIHR Southampton BRC and the University of Southampton was one of the study’s authors. He said:

“The surge in childhood obesity during the pandemic illustrates its profound impact on children’s development.

“Our projection that this will result in over £8.7 billion in additional healthcare, economic and wider social costs is hugely concerning.

“Alongside the even higher costs of the ongoing epidemic of childhood obesity, it is clear that we need more radical new policy measures. This will help reduce obesity and secure wellbeing and prosperity for the country as a whole.”

Co-author Emeritus Professor Mark Hanson, also from the NIHR Southampton BRC, added: “Once established, obesity has proven to be difficult to reverse. 60-85% of children with obesity remain obese in adulthood, increasing their risks of future ill health.

“Our finding of a rapid return to pre-pandemic levels of overweight and obesity in the youngest children suggests new policies should target under-fives. This is likely to be an effective means of tackling the growing problem of childhood obesity.”

Tackling inequalities and supporting young people

The costs of childhood obesity do not fall equally across the population.

Analysis of the NCMP data revealed that children living in the most deprived areas are twice as likely to be obese than those living in the least deprived areas. This means they will face higher lifelong economic costs compared to wealthier populations.

Promoting healthy behaviours in early life can help prevent obesity.

In Southampton, Early LifeLab is helping to tackle obesity among primary school children. It uses a series of ‘teaching toolkits’ to make the science behind the need for healthy diet, physical activity and sleep accessible to young children.

The programme is run in partnership between the University of Southampton, the NIHR Southampton BRC and University Hospital Southampton. It is part-funded by Southampton City Council.

Dr Kath Woods-Townsend, programme lead for Early LifeLab and a co-author on the paper, said:

“These findings show the importance of establishing healthy behaviours from an early age.

“We show children and young people how the choices they make and the habits they form can affect their health in later life. This gives them the knowledge and skills they need to make positive changes.”