Does the relationship between body mass index and health-related quality of life vary depending on early, middle and later adulthood?

OBJECTIVE: This study investigated the association between body mass index (BMI) and health-related quality of life (HRQoL) in a Korean adult population using a nationwide population-based survey. DESIGN: Cross-sectional study. SETTING: This study analysed data from the 2021 Community Health Survey in South Korea. PARTICIPANTS: A total of 223 336 respondents were aged ≥19 years. RESULTS: Underweight status was consistently associated with lower EuroQol HRQoL (EQ-5D) index scores across all age groups (early, middle and later adulthood), with the detrimental impact being most pronounced in men and the elderly (≥65 years). Specifically, underweight men aged 40-64 years exhibited the highest risk for problems in anxiety/depression (OR 2.48; 95% CI 1.86 to 3.30).The association between obesity and HRQoL showed different patterns depending on sex. In women, obesity was negatively associated with HRQoL across all life stages; notably, young women (19-39) with preobesity or obesity reported difficulties in all five EQ-5D dimensions. Conversely, in men aged ≥40 years, obesity was associated with better HRQoL outcomes and lower odds of anxiety/depression among those aged 40-64 years (OR 0.85; 95% CI 0.77 to 0.94) and those aged ≥65 years (OR 0.88; 95% CI 0.79 to 0.98). CONCLUSIONS: The association between BMI and HRQoL differs according to sex and age. Policy attention regarding HRQoL may benefit from considering the maintenance of proper weight and the promotion of nutritional health, tailored to sex and age.