Work engagement and its association with obesity and lifestyle factors in a large working population: a sex-stratified analysis

Background: Work engagement, defined as a positive, fulfilling psychological state characterized by vigor, dedication, and absorption, has been proposed as a potential protective factor for cardiometabolic health. However, its relationship with obesity-particularly visceral adiposity-remains poorly understood. This study aimed to examine the association between work engagement and different adiposity indicators and to explore the mediating role of lifestyle behaviors in a large sample of Spanish workers. Methods: A cross-sectional analysis was conducted among employees attending occupational health evaluations between 2021 and 2022. After applying inclusion and exclusion criteria, 111,612 participants (60.1% men) were included. Work engagement was assessed using the Utrecht Work Engagement Scale (UWES-9) and categorized into very high, high, moderate, and low levels. Obesity and adiposity were evaluated through BMI, waist-to-height ratio (WtHR), CUN-BAE, and METS-VF. Logistic regression models estimated odds ratios (OR) and 95% confidence intervals (CI) for obesity outcomes across engagement levels, with progressive adjustment for sociodemographic and lifestyle covariates. Mediation analyses evaluated the indirect effects of physical activity, Mediterranean diet adherence, and smoking. Results: Lower engagement levels were independently associated with higher odds of adiposity across all indices, particularly visceral fat (METS-VF). Participants with low engagement had an adjusted OR = 2.59 (95% CI 2.34-2.85) for high METS-VF compared with those with very high engagement (p-trend < 0.001). Approximately 40% of this association was mediated by lifestyle factors, mainly physical activity. The results remained robust across sensitivity analyses, including nonlinear modeling, imputation, and cluster adjustment. Conclusions: Lower work engagement is strongly associated with increased visceral adiposity among Spanish workers, partly through behavioral mechanisms. Enhancing engagement may represent an effective psychosocial strategy to improve both psychological well-being and metabolic health in occupational settings.