National trends in the prevalence of self-perceived overweight among adolescents, 2005-2022: a nationwide representative study in South Korea

Background: 

Despite several studies on self-evaluation of health and body shape, existing research on the risk factors of self-perceived overweight is insufficient, especially during the COVID-19 pandemic. 

Objective: 

This study focuses on elucidating the impact of risk factors on self-perceived overweight and how the prevalence of self-perceived overweight changed before and during the COVID-19 pandemic era.

Methods: 

The data used in the study was obtained from middle and high school students who participated   in   the   Korean   Youth   Risk   Behavior   Web-based   Survey   (KYRBS;   total n=1,189,586). We grouped the survey results by years and estimated the slope in prevalence of self-perceived overweight before and during the pandemic, as well as the prevalence tendencies of self-perceived overweight according to various risk factors.

Results:  

The   prevalence   of   self-perceived   overweight   is   much   higher   than   BMI-based overweight among 1,189,586 middle and high school participants (grade 7th-12th) from 2005 to 2022 (female; 577,102 [48.51%]). From 2005 to 2019 (pre-pandemic) the prevalence of self-perceived overweight increased (β, 2.80 [95% CI, 2.70-2.90]), but from 2020 to 2022 (pandemic) decreased (-0.53 [-0.74 to -0.33]).

 During the pandemic, individuals with higher levels of stress or lower economic status of households exhibited a more significant decrease in the rate of self-perceived overweight. 

The prevalence of self-perceived overweight tends to

be higher among individuals with lower school performance, lower economic status, poorer subjective health and higher stress level.

Conclusions: 

This nationwide study conducted over 18 years indicates that the prevalence of self-perceived overweight decreased during the COVID-19 pandemic. These findings suggest the necessity of facilities and policies for treatment of eating disorders and mental illnesses especially for adolescents with risk factors.