Abstract
BACKGROUND: Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are widely used to improve glycemic control and induce weight loss in individuals with type 2 diabetes (T2D), yet treatment responses vary significantly among individuals. Eating behavior has been hypothesized to influence therapeutic efficacy, but supporting evidence remains limited. METHODS: In this multicenter, prospective observational study, we enrolled 92 individuals with T2D initiating GLP-1RA therapy (liraglutide, dulaglutide, oral semaglutide, or injectable semaglutide) at four institutions in Gifu Prefecture, Japan. Participants were assessed at baseline, 3 months, and 12 months for clinical parameters, dietary intake, and eating behaviors using validated tools (Food Frequency Questionnaire and the Japanese version of the Dutch Eating Behavior Questionnaire [DEBQ-J]). Primary and secondary outcomes included changes in HbA1c, body weight, and eating behavior patterns over 12 months. RESULTS: GLP-1RA therapy significantly reduced HbA1c, body weight, and body fat percentage at 12 months. Notably, external eating scores showed a sustained decrease, while emotional and restrained eating scores exhibited transient changes. Higher baseline external eating scores were independently associated with greater weight reduction and showed a trend toward enhanced glycemic improvement. No significant associations were observed between emotional or restrained eating scores and clinical outcomes. CONCLUSION: This study demonstrates that GLP-1RAs improve both metabolic parameters and external eating behavior in T2D individuals. External eating emerged as a potential behavioral marker predictive of treatment response. These findings suggest that integrating eating behavior assessments may help personalize GLP-1RA therapy and optimize outcomes in clinical practice. CLINICAL TRIAL REGISTRATION: UMIN Clinical Trials identifier, UMIN000045362.