Impact of COVID-19 on Childhood Obesity in South Korea: Variations by Age and Sex

Background: The prevalence of overweight and obesity among children and adolescents has risen over recent decades, although the increase has recently stabilized. The coronavirus disease 2019 (COVID-19) pandemic was accompanied by substantial weight gain among Korean children. We examined changes in the prevalence of overweight and obesity among South Korean children from 2017 to 2021, including the pandemic period. Methods: We analyzed data from the Korea National Health and Nutrition Examination Survey from 2017 to 2021 to compare the prevalence of overweight and obesity before and during the COVID-19 pandemic. The study included 6,249 participants, with subgroup analyses by sex and age (2-9 and 10-18 years). Changes in lifestyle among adolescents aged 12-18 years were assessed using survey responses. Results: <0.05). Among children aged 10-18 years, boys had a notable increase in obesity prevalence during the pandemic, whereas girls did not have a statistically significant increase. Conclusion: The COVID-19 pandemic period was associated with a marked increase in the overall prevalence of obesity and extreme obesity among Korean children, particularly boys aged 10-18 years. Differences in lifestyle factors by sex and age may have contributed to the observed variation in obesity prevalence.