Background: The present post hoc analysis investigated whether changes in endogenous glucagon-like peptide-1 (Delta GLP-1) levels are associated with weight loss in newly diagnosed diabetes patients. Methods: In all, 784 subjects from the Metformin and AcaRbose in Chinese as initial Hypoglycemic treatment (MARCH) study were stratified according to Delta GLP-1. Changes in clinical and physiological parameters were evaluated across Delta GLP-1 subgroups (low, medium, and high) to assess correlations between Delta GLP-1 and weight loss in acarbose-versus metformin-treated groups. Results: After 24 weeks treatment, greater Delta GLP-1 was associated with significantly greater weight loss (-2 vs -1 kg in the medium/high vs low Delta GLP-1 groups, respectively) and reduction in body mass index (BMI; -0.88, -0.83, and -0.69 kg/m(2) in the high, medium, and low Delta GLP-1 groups, respectively). In the acarbose-treated group, there was a significant association between Delta GLP-1 and BMI reductions, and greater Delta GLP-1 across the high, medium, and low Delta GLP-1 groups was correlated with greater weight loss (-2.8, -2.1, and -1.9 kg, respectively) and reductions in fasting plasma glucose (-1.57, -1.28, and -1.02 mmol/L, respectively) at Week 24. No significant differences were found across Delta GLP-1 subgroups in metformin-treated patients (P > 0.05). Multivariate linear regression analysis revealed that gender, baseline BMI, and Delta GLP-1 at Week 24 were associated with weight loss. Baseline BMI and Delta GLP-1 in the acarbose-treated group and baseline BMI in the metformin-treated group predicted weight loss at Week 24. Conclusion: Changes in GLP-1 levels are associated with weight loss in newly diagnosed Chinese diabetes patients receiving acarbose.