Mapping the Associations Between Body Mass Index and Key Psychosocial Determinants: Resilience, Perceived Stress, and Emotion Regulation in Young Adults—A Cross-Sectional Study

<b>Background:</b> Obesity and overweight are escalating global public health concerns. This study examined the relationship between Body Mass Index (BMI) and psychological factors in young adults. <b>Methods:</b> A total of 283 participants aged 19-30 years were categorized by BMI (normal weight, overweight, obesity) using self-reported data. Psychological assessments included the Connor-Davidson Resilience Scale (CD-RISC), Perceived Stress Scale (PSS), Emotion Regulation Questionnaire (ERQ), and Buss-Perry Aggression Questionnaire (BPAQ), all with acceptable reliability. Individuals with psychiatric, neurological, or chronic somatic conditions were excluded. Analyses involved MANOVA, ANOVA, ANCOVA, and hierarchical regression, controlling for gender, physical activity, smoking, caffeine, alcohol, medication, and sleep disturbances. <b>Results:</b> MANOVA showed a near-significant multivariate effect of BMI on psychological variables (Wilks' Lambda = 0.913, <i>p</i> = 0.068). ANOVA revealed significant differences in perceived stress among BMI groups (F (2, 279) = 3.796, <i>p</i> = 0.024), with obese participants reporting lower stress. Hierarchical regression identified perceived stress as the strongest predictor of BMI, followed by resilience and physical aggression. General aggression was negatively associated with BMI, suggesting potential compensatory mechanisms. <b>Conclusions:</b> Perceived stress and resilience showed small but significant associations with BMI in young adults, suggesting a modest contribution of psychological factors to weight-related health.