Our study showed high levels of psychological distress and poor mental well-being in university students in Singapore, with female students reporting poorer mental health than their male counterparts. Students demonstrated low engagement in healthy movement and dietary behaviours, with particular concern for females students. Additionally, there was very low adherence to recommended sedentary behaviour and fruit intake. We found that engaging in a greater number of healthy behaviours was associated with lower psychological distress and better well-being. Female students who engaged in at least 2 or more healthy behaviours reported better mental health, whilst among male students, a significant association was found between 4–6 behaviours and mental health. Regarding specific type of behaviours, in both sexes, adequate sleep and limited unhealthy food intake were associated with lower psychological distress, and sufficient MVPA and adequate sleep were associated higher mental well-being. In addition, more MVPA and less sedentary behaviour were associated with better well-being in female students.
University students in our study reported higher levels of psychological distress than the general Singapore population.61 However, these levels appeared better than those reported by university students internationally.62,63,64 The mental well-being scores in our study population, collected during the COVID-19 pandemic, were also higher than those from other studies conducted in similar periods.65,66 Alarmingly, only 2% of students met the recommended fruit intake of two servings per day, which was lower than both local and international evidence.67,68 Similarly, low adherence to recommended sedentary behaviour was also observed.69,70 These findings resonate with global observations that cultivating multiple healthy lifestyle behaviours is a widespread challenge—only a minority of students managed to engage in multiple healthy behaviours.22,71,72,73
Our findings indicate that engaging in more healthy movement and dietary behaviours is associated with better mental health. Although a direct comparison with other studies is challenging due to differences in included behaviors and study populations, our results are consistent with the broader body of research.74,75,76 Movement and dietary behaviours appear to be closely related and positively influence each other.34 For instance, engaging in physical activity may have positive effects on sleep; shorter sleep duration is associated with unhealthy dietary behaviours; and sedentary behaviours may encourage passive snacking and overeating.28,77 It is plausible that these behaviours create a cumulative or synergistic relationship with mental health, where engaging in more healthy movement and dietary behaviours is associated with lower psychological distress and better mental well-being. Also, the problem behaviour theory posits that engaging in one unhealthy behaviour increases the likelihood of participating in another unhealthy behaviour.28,78 Addressing multiple behaviours simultaneously may be more efficient at improving mental health than a segmented approach that considers each behaviour individually.24,25,34,35,36,37
Whilst engaging in more healthy movement and dietary behaviours is strongly associated with better mental health outcomes, our findings suggest that the type of behaviours students engage in appears to play a role, too. Adequate sleep and limited unhealthy food intake were significantly associated with both mental health outcomes, aligning with findings from other studies.68,79,80,81,82 Evidence suggests that adherence to sleep guidelines was more strongly associated with reduced depression and anxiety than meeting the guidelines for sedentary behaviour or MVPA.33, 83 This could be due to the fact that sleep disturbance are often key symptoms of mental health conditions.84 Moreover, unhealthy food choices frequently serve as an accessible means to reduce stress through sensory pleasure, distraction, or escapism.79 Interestingly, our study found that sufficient MVPA was associated only with better mental well-being. This might be because persistent stressors such as academic performance pressure and concerns about future employment still maintain a certain level of psychological distress in this study population, despite engagement in physical activity. Contrary to some previous studies, our study did not find direct associations between fruit and vegetable intake and either of the two mental health outcomes.81,82,85 These discrepancies might be attributed to variations in measurements across studies. It's also plausible that fruit and vegetable consumption, as individual behaviours, may not be directly associated with mental health outcomes in our study population. However, when combined with other dietary or movement behaviours, they could contribute to better mental health.
Our study adds another dimension to the existing literature by considering sex differences. Overall, female students engaged in fewer healthy movement and dietary behaviours compared to male students. While the directions of the observed associations between the number of healthy behaviours and mental health outcomes were consistent for both sexes, the strength of associations appeared to be greater in female students.86,87,88,89 This may be due to the low engagement in healthy behaviours and poorer mental health in female students, potentially making them more responsive. Evidence also suggests a bi-directional relationship between movement and dietary behaviours and mental health: individuals with poor mental health reported more unhealthy movement and dietary behaviours.81,86, 90,91 This highlights the potential interplay of these aspects and the importance of addressing mental health conditions when promoting healthy lifestyle behaviours.92 An additional factor to consider is the mandatory two-year national service for Singaporean male citizens or permanent male residents at the age of 18.93 This service, including physical training and a regimented lifestyle, could influence health behaviours and potentially lead to greater mental resilience among male students. This unique contextual factor may contribute to the observed sex differences in our study and warrants future investigation in future research.
This study is among the first to explore the combination of movement and dietary behaviours and their associations with both positive and negative mental health outcomes. It contributes to our understanding of mental health promotion among university students in Asia. University students are at risk, as mental disorders have become one of the leading causes of morbidity, mortality, and dysfunction among young people worldwide.16 Whilst prevention and early intervention can be implemented throughout the lifespan, the potential benefits are substantial when targeting young people, an area currently lacking sufficient attention.16,18
As we strive to better promote mental health, several aspects worth considering for future research have emerged from our findings. First, our results provide insights into the potential interplay between movement and dietary behaviours and mental health. Recognising this interrelation underscores the need for interventions addressing both lifestyle behaviours and mental health holistically. Future interventions could benefit from adopting multi-faceted approaches that not only improve movement and diet behaviours but also incorporate components directly targeting mental health, such as stress management skills.92 Second, our findings support the importance of sex-tailored strategies when adopting a multi-faceted approach. Interventions are needed to exploit the responsiveness in females and acknowledge that males may need to engage in a higher level of health-promoting behaviours for comparable benefits. Lastly, the varying degrees of associations found between healthy behaviours and two mental health outcomes in this study advocate for future research to capture the broader spectrum of mental health.
Despite the novelty and strengths of the study, several limitations need to be acknowledged. First, as a cross-sectional study, it limits the ability to establish causality and reverse causality is possible. However, it does provide insights into the potential interplay and clustering of mental health outcomes and multiple health behaviours. Given that a cross-sectional study provides only a snapshot of the situation, future studies should leverage longitudinal designs with multiple data points to confirm the observed associations. Second, the use of self-report questionnaires introduces potential recall bias. Future research could benefit from including device-measured variables, particularly for assessing movement behaviours. Third, there remains a risk of residual confounding due to factors that our study may not have fully accounted for.