Impact of COVID‐19 pandemic on children overweight in Japan in 2020

Abstract

SummaryObjectivesThis study aimed to explore the association between the coronavirus disease (COVID‐19) pandemic and overweight incidence among preadolescent elementary school children in Japan.MethodsA population‐based longitudinal study was conducted in Adachi City, Tokyo, Japan, using data from the Adachi Child Health Impact of Living Difficulty (A‐CHILD) study. The control group (2016–2018) comprised 434 children, and the COVID‐19 exposure group (2018–2020) included 3500 children. Overweight was defined as a body mass index (BMI) z‐score of 1 SD or more according to the World Health Organization standards. The study design involved comparing BMI z‐scores before and after exposure to the pandemic, considering the associated lifestyle changes and potential consequences on physical activity, parental employment status and income.ResultsBy 6th grade, the prevalence of overweight increased from 17.7% to 19.2% in the control group and 22.5% to 29.5% in the COVID‐19 exposure group. Difference‐in‐differences analysis revealed that children's exposure to COVID‐19 significantly increased BMI z‐scores (coefficient 0.22, 95% confidence interval (CI) 0.14–0.29) and a higher odds ratio of overweight (odds ratio 2.51, 95% CI 1.12–5.62), even after adjusting for time‐varying covariates.ConclusionThe COVID‐19 pandemic has been associated with an increased prevalence of overweight among elementary school children in Japan.