Investigating the associations among overtime work, health behaviors, and health: A longitudinal study among full-time employees

Background: It has often been suggested that high levels of overtime lead to adverse health outcomes. One mechanism that may account for this association is that working overtime leads to elevated levels of stress, which could affect worker's behavioral decisions or habits (such as smoking and lack of physical activity). In turn, this could lead to adverse health. Purpose: The present study examined this reasoning in a prospective longitudinal design. Data from the prospective 2-year Study on Health at Work (N=649) were used to test our hypotheses. Methods: Structural equation analysis was used to examine the relationships among overtime, beneficial (exercising, intake of fruit and vegetables) and risky (smoking and drinking) health behaviors, and health indicators (BMI and subjective health). Results: Working overtime was longitudinally related with adverse subjective health, but not with body mass. Moreover, working overtime was associated with lower levels of physical activity and intake of fruit and vegetables, but not with smoking and drinking. Finally, higher levels of risky and lower levels of beneficial health behaviors were longitudinally associated with ill health. Conclusions: The relation between overtime and ill health is partly accounted for by the unhealthy lifestyle in which overworkers tend to engage. However, a direct longitudinal effect of overtime on health suggested that the effects of overtime on health may also partly be due to the sustained physiological activation that results from working overtime. Whereas working a moderate amount of overtime does not usually entail major health risks, these will increase with increasing overtime.