Rito, AnaMartins, Maria de FátimaGaspar, MartaDedoussis, George2026-02-092026-02-092025-05-11http://hdl.handle.net/10400.18/10860Abstract publicado em: Obes Facts. 2025;18(Suppl 1):485 (PO4.173). doi: 10.1159/000545547.Introduction: Obesity remains a critical global health challenge, contributing to the rising prevalence of non-communicable diseases and imposing substantial burdens on public health systems worldwide. Understanding the determinants of obesity is essential for designing effective and inclusive interventions. The BETTER4U project (2023–2027) aims to develop and implement a personalized lifestyle intervention, by addressing the multifaceted determinants of adult obesity. Data such as those provided by the Childhood Obesity Surveillance Initiative (COSI) offer critical insights into these determinants, supporting the design of tailored interventions. Socioeconomic vulnerabilities, in particular, have been consistently identified as key determinants of obesity, requiring targeted strategies to address their impact. Methods: COSI, conducted by WHO, not only collects data on the nutritional status of children aged 6–8 years, but also gathers family-level information self-reported by parents, including parental nutritional status (calculated BMI, classified according to the WHO reference) and socioeconomic factors. This study utilized data from the 5th (2018/2019) and 6th (2021/2022) rounds of COSI in Portugal to perform a cross-sectional observational analysis exploring the association between adult obesity and vulnerability factors. Participants were categorized into groups based on sex (female vs. male) and the following socioeconomic variables: educational level (lower vs. higher education), perceived family wealth (experiencing financial difficulties vs. not experiencing financial difficulties), occupation (employed/student vs. unemployed/sick/disabled), and residential setting (urban vs. rural). The aim was to identify the determinants of adult obesity to support the design of BETTER4U’s personalized intervention strategies, which will be implemented in seven European countries, including Portugal. Results: Of the 9169 adults included in this analysis, 12.2% had obesity and 21.6% reported financial difficulties. A binary logistic regression was conducted, considering a significance level of p<0.05. After adjusting for confounding factors (age, sex, education level, occupation and residential setting), financial difficulties emerged as a significant predictor of obesity. Adults facing financial challenges were nearly twice as likely to have obesity compared to those without such difficulties (adjusted Odds Ratio [aOR]: 1.88, 95% Confidence Interval [CI]: 1.639–2.162; p<0.001). Conclusions: This analysis demonstrates the critical role of financial difficulties in shaping obesity outcomes among adults, emphasizing the need for inclusive, tailored interventions to address the needs of at-risk populations and providing a robust foundation for BETTER4U’s innovative and evidence-based strategies for weight managementengSocioeconomic VulnerabilitiesObesityWeigh ManagementCOSIPortugalEstilos de Vida e Impacto na Saúdeconference object