The global rise in childhood obesity is a serious, long-term public health challenge and one that—warns a policy briefing from the World Obesity Federation published in November, 2020—could be exacerbated by the COVID-19 pandemic response. Given how dramatically the pandemic has affected food systems, the economy, and children's daily lives over the past 2 years, the potential impact of the pandemic on childhood obesity warrants careful scrutiny and a plan to get back on track towards reducing childhood obesity as part of the pandemic recovery.
Childhood obesity and overweight have increased substantially over the past four decades. WHO estimates that, in 2020, there were 39 million children under 5 years of age with overweight or obesity, and that the prevalence of obesity among those aged 5–19 years has increased from <1% globally in 1975 to 6% of girls and 8% of boys in 2016. Obesity and overweight can be associated with physical and mental health issues, and affect quality of life during childhood, but also increase the likelihood of being overweight and having life-limiting comorbidities in adulthood. Allowing childhood obesity levels to rise further could therefore translate into major health and economic challenges for future generations—not least vulnerability to pandemic outbreaks of viruses like COVID-19, for which overweight is an important risk factor.
Commercial and social determinants of health have fuelled the rapid, global growth in childhood overweight. Changes in food production, retail practices, and the wider food environment have meant an increasing availability of convenient, high-calorie foods and drinks, and, as highlighted in The Lancet Commission A Future For The World's Children, this has been coupled with aggressive and largely unregulated marketing of unhealthy products towards children and their parents. Changes in transportation and leisure habits mean that many children have increasingly sedentary lifestyles. Within societies, children from more deprived backgrounds are substantially more exposed to and affected by these social determinants of excess weight. The importance of the environment to health inequalities is reinforced in a study by Charis Staatz and colleagues in this issue of The Lancet Public Health, reporting that body mass trends over adolescence are associated with local area deprivation in a large UK cohort, even when controlling for family socioeconomic circumstances.
While some preliminary data on childhood overweight and obesity during the pandemic are becoming available, there is an urgent need to better understand the potential impact of the pandemic on children's health. School closures, strained household finances, increased screen time, and marketing of fast foods have increased exposure for many children during the pandemic to the environmental drivers of weight gain. For the most vulnerable children, school closures have often impeded their only source of regular, healthy meals, exacerbating the health divide between more and less deprived households.
In their 2016 Commission report on Ending Childhood Obesity, WHO outlined policies to address the determinants of obesity at a population level. However, the 2019 Global Atlas on Childhood Obesity reported that most countries were not doing enough to meet the WHO target of halting the growth in childhood overweight by 2025. Still, some positive steps have been taken. Recent examples include the partial ban on junk food advertising on TV and online in the UK announced this year and taxes on sugary drinks levied in Mexico. Bolder and more widespread actions are needed, such as those in the UK National Food Strategy independent review, published on July 15, 2021, advocating for taxes on foods with high sugar and salt contents to encourage reformulation, greater subsidised provision of healthy foods to children from deprived families, and funding for nutrition and cooking classes in schools.
As children return to schools, these institutions could play an even more important part in delivering healthy nutrition, and physical and food education. Importantly, there is an opportunity for greater intersectional collaboration between the education and health sectors, bringing wide ranging benefits to childhood development. The COVID-19 pandemic has highlighted weaknesses and inequalities in our societes, including across the food system. Recovery should be taken as an opportunity to rethink priorities of health versus commercial interests and protect children and adolescents.