Digital Augmentation of Glucagon-Like Peptide-1 for Obesity Management: Retrospective Study
Journal of Medical Internet Research ·
Background: Glucagon-like peptide-1 receptor agonists (GLP-1 RAs), including semaglutide and tirzepatide, are highly effective for weight management; however, long-term outcomes depend on sustained behavioral engagement. Digital health tools may enhance these behavioral components, but evidence regarding their real-world benefit alongside pharmacotherapy remains limited. Objective: This study aims to evaluate whether augmenting a direct-to-consumer GLP-1 RA program with a behavioral support smartphone app improves weight-loss outcomes compared with medication alone, and to identify which app features are associated with weight loss over time. Methods: A retrospective observational cohort study was conducted using data from 6113 adults (older than 18 years) in Australia who self-enrolled into the Mosh direct-to-consumer weight-loss program between July 1, 2024, and August 13, 2025, with their weight data recorded at baseline and at least 1 other timepoint. Participants received semaglutide or tirzepatide, with optional access to a smartphone app and clinician support. Logistic regression models examined achievement of ≥5%, ≥10%, and ≥15% weight-loss thresholds at 60, 120, and 180 days. Linear mixed-effects models interacting with app feature use, with linear and quadratic time terms, assessed the association of different features with percentage weight loss trajectories over time. Both models adjusted for medication type, gender, ethnicity, age, and baseline BMI. Results: Participants using the program plus medication had higher odds of achieving clinically significant weight loss than those using medication only. Adjusted odds ratio point estimates for day 60, 120, and 180 (±10) days indicated they were 1.38 (95% CI 1.09-1.75) times to 2.22 (95% CI 1.40-3.45) times more likely to achieve ≥5% weight loss across timepoints, 1.67 (95% CI 1.33-2.10) times to 1.97 (95% CI 1.35-2.90) times more likely to achieve ≥10% weight loss by day 120 and 180, and 1.99 (95% CI 1.26-3.29) times more likely to achieve ≥15% weight loss by 180 days. Mixed-effects modeling demonstrated that progress logging was associated with more rapid weight loss over time (β=.26 percentage-point additional weight lost per 30 days, SE 0.06; =4.46; 95% CI 0.14-0.38; <.001). No other app features were consistently associated with changes in weight-loss trajectories. Conclusions: Augmenting GLP-1 RA treatment with a behavioral smartphone app was associated with a higher likelihood of achieving clinically significant weight loss, although differences in overall weight-loss trajectories were modest. Progress logging emerged as the primary behavioral predictor of improved outcomes. While not causal effects, these findings are consistent with the positive value of integrating digital tools with pharmacotherapy for weight loss.