Association between eating behavior patterns and the therapeutic efficacy of GLP-1 receptor agonists in individuals with type 2 diabetes: a multicenter prospective observational study

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 .