PLOS One · Mar 20, 2026

Behavior-biological mismatch in metabolic health: Evidence from South Korean adults before, during, and after COVID-19 (KNHANES 2019-2022)

By Jeong YM, Kim M, Jeong JY

OBJECTIVE: Regular physical activity (PA) is recommended for cardiometabolic prevention, yet emerging evidence suggests that meeting PA guidelines alone does not guarantee metabolic health. Pandemic-related disruptions may have intensified behavior-biology discrepancies. This study examined the prevalence and sociodemographic determinants of the physically active but metabolically unhealthy (PA-NH) group before, during, and after the COVID-19 pandemic in Korea. METHODS: We analyzed 17,719 adults aged ≥19 years using the 2019-2022 Korea National Health and Nutrition Examination Survey. Participants were classified into four groups: PA-H, NPA-H, NPA-NH, and PA-NH. Temporal patterns across the pre- (2019), during- (2020-2021), and post-pandemic period (2022) were assessed using χ² tests and ANOVA. Multinomial logistic regression identified determinants of PA-NH membership. RESULTS: From 2019 to 2022, PA-H declined during the pandemic and rebounded thereafter, whereas PA-NH increased from 31.2% to 34.0%. Older adults had markedly higher odds of PA-NH (OR 7.30 for ≥70 y vs 19-29 y). Women were less likely to belong to PA-NH. Higher education reduced the odds of mismatch relative to PA-H but increased them compared with NPA-NH. Metabolic risk factors such as hypertension and hypercholesterolemia rose despite recovery in PA. CONCLUSIONS: The persistence and rise of PA-NH after the pandemic show an association suggesting that adherence to PA guidelines alone is insufficient for cardiometabolic protection. Post-pandemic public health strategies should integrate aerobic and resistance exercise with dietary modification, stress management, and routine screening, prioritizing older adults and other high-risk groups.

doi.org/10.1371/journal.pone.0344918Open accessPubMed 41860976Populations