Associations Between Energy Balance-Related Behaviours and Childhood Obesity Among Vulnerable Populations in Greece: Implications for Public Health Policy and Intervention Development

<b>Background/Objectives</b>: Childhood obesity remains a critical public health concern in Greece, particularly among socioeconomically vulnerable groups. This study conducted a secondary analysis of five large-scale epidemiological datasets to examine the association between energy balance-related behaviours (EBRBs) and obesity in children in need. <b>Methods</b>: Data were compiled from five nationally or regionally representative studies (Genesis, ToyBox, Healthy Growth, ENERGY, and Feel4Diabetes) involving children aged 1-12 years. Stratified and subgroup analyses were performed to examine associations between weight status and EBRBs, including dietary habits, physical activity, and sedentary behaviour. Determinants of EBRBs were also analysed using the socio-ecological model framework. <b>Results</b>: Children in need demonstrated a higher prevalence of overweight and obesity compared to the general child population. Key risk factors for EBRBs included frequent consumption of sugar-sweetened beverages, sweet snacks, and high screen time. Protective behaviours associated with lower obesity risk included regular breakfast consumption, adequate sleep duration, and physical activity. Determinants of high-risk EBRBs were primarily interpersonal and, to a lesser extent, individual and community-level factors. <b>Conclusions</b>: These findings highlight the disproportionate burden of childhood obesity among vulnerable populations and identify modifiable behaviours and determinants that can inform targeted interventions. These results provide a robust evidence base to guide national public health policies, including the development of school- and community-based obesity prevention programmes aligned with the goals of Greece's National Action Against Childhood Obesity. Prioritising children in need in such initiatives is essential to reduce health inequities and improve long-term health outcomes.