Publication date: Sep 01, 2026
We examined trends in physical activity (PA), sedentary behavior (SB), and weight status among Korean adolescents across the COVID-19 period and assessed subgroup disparities. We analyzed nationally representative data from the 2017 to 2024 Korea youth risk behavior web-based survey (N = 417,243; mean age, 15. 0 years). PA adherence followed World Health Organization recommendations; SB adherence was defined as ≤ 2 h/day of recreational screen time; and weight status used the 2017 Korean Growth Chart BMI percentiles. Weighted estimates and Joinpoint regression quantified annual percent changes (APCs). Underweight and obesity both increased. Underweight rose particularly among girls (APC, 6. 7%), whereas obesity was more prevalent among boys (14. 7%; APC, 3. 2%) and high school students (13. 3%; APC, 3. 2%). PA adherence increased over the study period (APC, 4. 0%) but remained low, especially in girls (2. 4% vs. 8. 6% in boys). SB adherence declined from 36. 1% in 2017 to 19. 2% in 2020 and partially recovered by 2024 (24. 5%). Schools should adopt gender-sensitive strategies to increase daily PA and reduce recreational SB, prioritizing girls and high school students. From 2017 to 2024, weight polarization worsened among Korean adolescents, underscoring the need for equitable school-based interventions targeting PA, SB, and weight-related disparities.

Semantics
| Type | Source | Name |
|---|---|---|
| disease | MESH | COVID-19 |
| disease | MESH | Underweight |
| disease | MESH | obesity |
| disease | MESH | APC |
| disease | MESH | Body Weight |
| disease | MESH | Pediatric Obesity |