While it seems that COVID happened a decade ago, it has only been 4 years since the pandemic came to this part of the world. New research examines what the effect of the pandemic has been on obesity among children. And there is good and bad news:

Obesity among primary school children in the UK spiked during the COVID-19 lockdown, with a 45% increase between 2019/20 and 2020/21 among 4-5-year-olds, according to a new study. The authors estimated that without reversals, increased obesity rates in Year 6 children alone will cost society an additional 800 million in healthcare.

Obesity among primary school children in the UK spiked during the COVID-19 lockdown, with a 45% increase between 2019/20 and 2020/21 among 4-5-year-olds, according to a study published on January 24, 2024 in the open-access journal PLOS ONE by Iván Ochoa-Moreno from the University of Southampton, UK, and colleagues. The authors estimated that without reversals, increased obesity rates in Year 6 children alone will cost society an additional £800 million in healthcare.

During the first year of the pandemic, school closures dramatically altered the routines of young children. Cancellation of organized sports, disrupted sleep schedules, more screen time, and deterioration of healthy eating habits likely contributed to the largest single-year increase in overweight and obesity prevalence seen in children in decades. To better understand the long-term health and economic costs of rising obesity rates in young children, the authors of the study compared Body Mass Index (BMI) data from England’s National Childhood Measurement Programme (NCMP) before, during, and after the COVID-19 pandemic among children in their first and last years of primary school (aged 4-5 and 10-11 years old). Using data from two additional longitudinal cohorts in the UK, they modeled the impact of these BMI trends on adult health outcomes and costs.

The researchers observed a 45% increase in obesity prevalence during 2020-2021 in children between 4-5 years old, and a similar effect in Year 6 children. This increase was twice as high in the most deprived areas of England. While the number of overweight and obese 4-5 year olds returned to pre-pandemic levels the following year, the increases seen in older children persisted into 2022. The study estimated that this group of children will cost society an additional £800 million in healthcare, for conditions like type 2 diabetes and heart disease, over their lifetimes.

The researchers state that the persistence of weight gain in older children suggests that reversing obesity is very challenging in older age groups, while the quick reversal to pre-pandemic levels in young children highlights the promise of policies targeting children under five as a strategy to tackle obesity.

One of the study’s authors, Professor Keith Godfrey, adds: “The sharp increase in childhood obesity during the COVID-19 pandemic illustrates the profound impacts on children’s development. Alongside the escalating costs of the ongoing epidemic of childhood obesity, it is clear that more radical new policy measures are required to reduce obesity and secure wellbeing and prosperity for the country as a whole.”

Abstract of the study (open access):

Background
The prevalence of overweight and obesity in young children rose sharply during the COVID-19 pandemic. Here we estimate the potential future health and economic effects of these trends in England.

Methods
Using publicly available annual Body Mass Index (BMI) data from 2006–2022, we calculated the increase in overweight/obesity prevalence (BMI ≥85th reference percentile) during the COVID-19 pandemic among children aged 4–5 and 10–11, and variation by deprivation and ethnicity. We projected the impact of child BMI trends on adult health measures to estimate added lifelong medical and social costs.

Results
During 2020–2021 there were steep increases in overweight and obesity prevalence in children. By 2022, overweight and obesity prevalence in children aged 4–5 returned to expected levels based on pre-pandemic trends. However, overweight and obesity prevalence in children aged 10–11 persisted and was 4 percentage points (p<0.001) higher than expected, representing almost 56,000 additional children. The increase was twice as high in the most compared with the least deprived areas. The additional lifelong healthcare cost in this cohort will amount to £800 million with a cost to society of £8.7 billion. We did not find an increase in maternal obesity associated with the COVID-19 pandemic, however, prevalence grew faster in the post pandemic period.

Discussion
The return of overweight and obesity prevalence to pre-pandemic trends in children aged 4–5 provides a clear policy target for effective intervention to tackle this growing and serious population health concern