Healthy lifestyle behaviors and persistent socioeconomic inequalities in health-related quality of life: Evidence from a population-based study in Turkey

Purpose Health-related quality of life (HRQoL) is a key indicator of population well-being; however, limited evidence documents how lifestyle behaviors relate to HRQoL and its socioeconomic gradient in Turkey. This study assessed overall HRQoL levels, examined the associations between healthy lifestyle behaviors and HRQoL, and evaluated whether lifestyle factors mitigate income-related disparities among adults aged 18–64. Methods Data were obtained from the nationally representative 2014–2022 Turkey Health Survey (N = 61,362). HRQoL was measured using the EQ-5D-3L with UK TTO tariffs. A Healthy Lifestyle Score (0–5) included smoking status, alcohol consumption, physical activity, diet, and BMI. Survey-weighted OLS regressions estimated associations between lifestyle behaviors and HRQoL, and an interaction term tested whether these associations differed by income level. Sensitivity analyses assessed the contribution of individual lifestyle components. Results Mean HRQoL was moderate (EQ-5D = 0.687) and substantially lower among adults with lower income. Pain/discomfort and anxiety/depression were the most impaired domains. Healthier lifestyle behaviors were positively associated with HRQoL, with non-smoking, a healthy diet, and maintaining a BMI within the recommended range showing the strongest associations. These benefits were more pronounced among lower-income adults; however, income-based inequalities in HRQoL persisted across all levels of lifestyle behaviors. Conclusion Healthy lifestyle behaviors play an important role in shaping HRQoL and yield enhanced benefits for socioeconomically disadvantaged adults. Nonetheless, lifestyle improvements alone are insufficient to eliminate income-related inequalities. Addressing both behavioral and structural determinants is essential for improving HRQoL and reducing socioeconomic disparities.