Clusters of healthy lifestyle behaviours are associated with symptoms of depression, anxiety, and psychological distress: A systematic review and meta-analysis of observational studies.

Engagement in healthy and unhealthy lifestyle behaviours are related to a range of mental health outcomes. Most existing research has focussed on individual lifestyle behaviours, so it is not clear the extent to which clusters of healthy lifestyle behaviours relate to mental health outcomes. Therefore, this study aimed to systematically review and quantitatively synthesise research which have examined the association between clusters of lifestyle behaviours with symptoms of depression, anxiety, and psychological distress. A systematic search of five electronic databases were conducted to identify studies which used person-centred approaches (e.g., cluster analysis, latent class analysis) to identify subgroups of participants based on at least two unique lifestyle behaviours (i.e., physical activity/sedentary behaviours, diet, sleep, alcohol/tobacco/drug use) and examined differences in symptoms of depression, anxiety, or psychological distress between clusters. A correlated and hierarchical random effects meta-analysis was used to synthesise the results. A total of 81 studies reporting on nearly one-million individual participants were included in the review. Results demonstrated that participants who engaged in the healthiest clusters of lifestyle behaviours reported significantly fewer symptoms of depression (SMD = -0.41), anxiety (SMD = -0.43) and psychological distress (SMD = -0.34) compared to participants engaging in less healthy combinations of lifestyle behaviours, and a dose response relationship was observed across outcomes. These results demonstrate that there is a moderate-to-strong relationship between engaging in clusters of healthy lifestyle behaviours and mental health outcomes and demonstrate the importance of considering healthy lifestyle as a whole instead of as individual parts.