The unequal weight of COVID-19 pandemic: national trends in body mass index among Korean adolescents by immigrant-origin and gender from 2013 to 2022

The COVID-19 pandemic increased the burden due to school closures and stay-at-home orders, disrupting the community energy balance. This study examines rising obesity trends among Korean adolescents during school closures, focusing on gender differences and immigrant-origin youths - those of foreign descent or with at least one foreign-born parent. We analysed data from the Korea Youth Risk Behavior Web-based Survey (KYRBS) (N = 539,187). The study aims to assess BMI trends between 2013 and 2022, examine the impact of school closures, and explore differential obesity risks among immigrant-origin youths by gender. Regression models with interaction terms were used to analyse BMI trends and pandemic effects on immigrant-origin youths compared to non-immigrant-origin youths, with gender subgroup analyses. Results show increased BMI for all adolescents, with a notable rise and higher overweight risks in immigrant-origin male adolescents during COVID-19. These findings highlight the need for gender-specific interventions in schools for immigrant-origin youths.