SAT-709 - Digital Programme Engagement Substantially Enhances Weight Loss in Adults with Obesity Treated with GLP-1 Receptor Agonists: A Retrospective Analysis of 240,311 Participants

Introduction: GLP-1 receptor agonists (GLP-1RAs) have transformed obesity pharmacotherapy, yet real-world effectiveness depends upon sustained behavioural engagement. Digital health programmes offering coaching, self-monitoring, and automated support may augment pharmacological efficacy, though large-scale evidence remains limited.

Methods: We conducted a retrospective cohort study of adults (aged 18-75 years; BMI ≥30 kg/m² or ≥27 kg/m² with comorbidities) initiating tirzepatide or semaglutide via a UK digital weight management service between February 2023 and December 2025. Full engagement was defined as attendance at ≥1 coaching session, ≥4 weekly weight logs, and ≥1 app login during follow-up. Percentage weight change was analysed at months 1 to 12 using mixed-model repeated measures (MMRM) adjusted for age, sex, baseline weight, and comorbidities. Time-to-event analyses assessed attainment of clinically significant weight loss thresholds (≥5%, ≥10%, ≥15%, ≥20%, ≥25%). Hazard ratios (HR) were estimated using Cox proportional hazards regression.

Results: Among 240,311 participants (mean age 43.5 ± 12.6 years; 80.3% female; mean BMI 34.8 ± 6.1 kg/m²), 23,108 (9.6%) were fully engaged. At month 12, engaged participants achieved significantly greater adjusted weight loss (-22.1%; 95% CI -22.3 to -21.9) compared with non-engaged participants (-16.1%; 95% CI -16.3 to -16.0; P< 0.001; Cohen's d=0.57). Differences emerged by month 1 (-5.9% vs -4.5%; P< 0.001) and widened progressively. Engaged participants reached all weight loss thresholds more rapidly: HR 2.99 (95% CI 2.94-3.04) for ≥5%; HR 2.54 (2.49-2.59) for ≥10%; HR 2.22 (2.17-2.28) for ≥15%; HR 2.01 (1.95-2.08) for ≥20%; and HR 1.91 (1.83-2.00) for ≥25% (all P< 0.001). By month 12, 40.5% of engaged participants achieved ≥20% weight loss versus 17.1% of non-engaged participants.

Conclusion: Digital programme engagement substantially amplifies and accelerates GLP-1RA-associated weight loss in real-world practice. To the best of the authors' knowledge, this represents the largest study examining digital engagement with incretin therapy to date. Whilst the observational design cannot exclude confounding by intrinsic motivation, the magnitude and consistency of effects across all weight loss thresholds supports integrating structured digital support with pharmacotherapy as a strategy for optimising obesity management outcomes.

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