Morningness-eveningness interferes with perceived health, physical activity, diet and stress levels in working women: a cross-sectional study.

Sleep and health are closely interrelated and sleep quality is a well-known contributor to perceived health. However, effects of sleep-timing preference i.e. morningness-eveningness on health has yet to be revealed. In this study, we explored the relationship between morningness-eveningness and perceived health in a sample of female working professionals (N = 202). Sleep-timing preference was measured using the Composite Scale of Morningness. Perceived health was characterized by Center for Epidemiologic Studies Depression Scale, WHO Well-Being Scale-5 and Patient Health Questionnaire-15 scores. We also investigated possible mechanisms, including stress and health-impairing behaviours. In accordance with previous data, we found more depressive mood, lower well-being and poorer perceived health among evening types. To assess health-impairing behaviours we collected data on smoking habits, alcohol consumption, physical activity and diet. Among the possible mechanism variables, greater stress, less frequent physical activity and less healthy diet were associated with eveningness. Furthermore, stress diminished the strength of the association between morningness-eveningness and depressed mood. Physical activity attenuated the strength of the association between morningness-eveningness and well-being. No effects of alcohol consumption could be identified. Our data show that evening preference behaves as a health risk in terms of associating with poor perceived health. Our findings also suggest that this effect might be mediated by health behaviours and stress.