Nutrition knowledge, attitude, and practice in relation to health-related quality of life among urban-poor children in Malaysia: the mediating role of lifestyle factors

BACKGROUND: Children living in urban-poor communities are particularly vulnerable to poor health-related quality of life (HRQoL) because socioeconomic disadvantage, food insecurity, constrained food environments, and limited access to health-promoting resources may affect both nutritional status and psychosocial well-being. Although nutrition knowledge, attitude, and practice (KAP) are known to influence children's health behaviours, the behavioural pathways through which these factors affect HRQoL remain insufficiently understood. This study examined the interrelationships between nutrition KAP, lifestyle-related behaviours, body composition, and HRQoL among children from urban-poor flats using serial mediation analysis. METHODS: A cross-sectional study was conducted using cluster sampling to recruit eligible participants from ten urban-poor flats in Kuala Lumpur, Malaysia. Participants completed a sociodemographic questionnaire, nutrition knowledge, attitude, and practice (KAP) questionnaire, Eating Behaviours Questionnaire (EBQ), Physical Activity Questionnaire for Older Children (PAQ-C), and Pediatric Quality of Life Inventory™ (PedsQL™) 4.0. The body composition of the children was also measured using InBody 270s bioelectrical impedance analysis. Serial mediation analysis was conducted through path analysis to evaluate the inter-relationships between variables. RESULTS: A total of 408 children (mean age = 9.7 years) were recruited. Nutrition attitude significantly mediated the relationship between nutrition knowledge and nutrition practice (b = 0.034, 95% CI: 0.019, 0.054). Nutrition knowledge showed no significant direct effect on HRQoL but demonstrated significant indirect effects through multiple behavioural pathways (p < 0.05), particularly through nutrition attitude, nutrition practice, fast-food intake, supper intake, and physical activity. The final model explained 32.1% of the variance in HRQoL. CONCLUSION: These findings suggest that nutrition KAP influences HRQoL primarily through modifiable lifestyle-related behaviours rather than through a direct pathway. Interventions for children in urban-poor communities should therefore combine nutrition knowledge enhancement with strategies that strengthen attitudes, support healthier practices, reduce unhealthy eating behaviours, and promote physical activity.