Sleep, movement, and dietary behaviours: the mediating role of affect.

Background: Previous studies indicated a link between good sleep, optimal movement, and a healthy diet, but the underlying mechanisms are poorly understood. This diary study aimed to investigate the effects of sleep behaviour on movement and dietary behaviours as well as the mediating role of affect.

Method: One hundred and twenty college students completed twice daily assessments of health behaviours and affect for 28 days. Multilevel structural equation modelling was used to examine the relationships between sleep, health behaviours, and the mediating role of affect.

Results: At the between-person level, sufficient sleep was associated with less overeating. At the within-person level, sleep duration predicted less sedentary behaviour, while sufficient sleep predicted higher water intake and more sedentary behaviour. Negative affect mediated the relationship between sleep quality/duration and exercise measures (events, duration), while positive affect mediated the relationships between sleep quality/duration and overeating, exercise measures, and sedentary behaviour. Positive affect mediated the relationships between sufficient sleep, exercise measures, and sedentary behaviour.

Conclusion: Sleep can indirectly influence other health behaviours by decreasing negative affect or increasing positive affect. These findings emphasise the significance of sleep in promoting a healthy lifestyle and the role of affect, especially positive affect, in this process.