Behavioral, Psychological, and Metabolic Characteristics of Adults with Co-Occurring Generalized Anxiety Disorder and Obesity: A Cross-Sectional Study

Background: Generalized Anxiety Disorder (GAD) and obesity are highly prevalent and often co-occur, yet it remains unclear how the presence of both conditions relates to biological, behavioral, and psychological outcomes compared with either condition alone. Understanding this subgroup is crucial to improving assessments and treatment outcomes. Objective: To characterize biological, psychological, and behavioral parameters among individuals living with obesity (LWO) and GAD (GAD + LWO), compared with those with only one condition (GAD or LWO) and healthy controls. The primary outcome was to characterize binge eating severity, assessed using the Binge Eating Scale (BES). All remaining behavioral, psychological, and biological outcomes were considered secondary evaluated outcomes. Methods: This cross-sectional study included 232 adults: GAD + LWO (n = 73), GAD only (n = 52), LWO only (n = 53), and controls (n = 54). Participants completed validated psychological measurements and eating behavior assessments and underwent clinical and metabolic evaluations, including insulin resistance (HOMA-IR) and C-Reactive Protein (CRP). Statistical analyses were performed using analysis of covariance (ANCOVA) for group comparisons and additional interaction analyses between GAD diagnosis and obesity status, adjusted for age and sex. Results: Binge eating severity was significantly higher in the GAD + LWO group than in all other groups, with the group mean exceeding the screening threshold for moderate binge eating. This group also showed significantly higher levels of depressive symptoms, emotional eating and impulsivity compared to all other groups. Factorial analyses showed a significant GAD diagnosis × obesity interaction only for depressive symptom severity. Compared to the LWO group, individuals with GAD + LWO also exhibited higher emotional dysregulation, neuroticism, and shame. Biologically, this group showed elevated insulin resistance and higher proportions of systemic inflammation (CRP > 3.0 mg/L) in comparison with the GAD group, but similar to the LWO group. Conclusions: The co-occurrence of GAD and LWO was associated with greater severity across several behavioral and psychological outcomes compared with either condition alone. These findings highlight the potential role of tailored, integrated interventions that extend beyond standard obesity treatment to address eating behavior and self-regulation difficulties. Future prospective studies are needed to confirm these exploratory findings and determine their relevance for long-term treatment outcomes and relapse risk.