Changes in weight and height among Chinese preschool children during COVID-19 school closures.

Background and objectives COVID-19-related school closures may increase the prevalence of childhood obesity, which has aroused public concerns. We aimed to analyze the weight and height changes in Chinese preschool children during the COVID-19-related school closures period. Methods A total of 124,603 children from multi-city kindergartens in China were included in this study. We evaluated the prevalence of overweight and obese in preschool children experienced school closures, and compared the changes in BMI, weight, and height of preschool children among COVID-19 school closures period, the same period last year and the same period the year before last. Results After the school closures, childhood obesity prevalence increased, whereas overweight prevalence decreased. During school closures, the average increase in height was about 1 cm less as compared with the same period last year and the year before last, but no noteworthy difference in the weight change was observed among the three periods. Conclusions During COVID-19 school closures, children's height increase seemed to be more affected than weight change. Innovative, robust, and highly adaptable strategies should be taken to increase physical activity, reduce sedentary time and promote healthy diets, to minimize the adverse impact of school closures.