Two-Year Weight Loss With GLP-1 Medications Compared With Sleeve Gastrectomy in Adults With Obesity

Inclusion Criteria: GLP-1 Receptor Agonist Cohort: * Age 18 years or older at treatment initiation. * Initiation of a GLP-1 receptor agonist for obesity or overweight as part of routine clinical care. * Available baseline height and body weight measurements. * Willingness to attend at least one follow-up assessment. * Ability to comply with the center's standard follow-up program. * Provision of written informed consent. Laparoscopic Sleeve Gastrectomy Cohort: * Age 18 years or older at surgery. * Primary laparoscopic sleeve gastrectomy for obesity performed at the study center between January 1, 2020, and January 1, 2026. * Available preoperative height, body weight, and body mass index measurements. * Available demographic and baseline clinical data. * At least one documented postoperative body weight measurement. Availability of a 24-month weight measurement is preferred for the primary comparison. Exclusion Criteria: Both Cohorts: * Bariatric or metabolic surgery before the index treatment. * Revisional bariatric surgery as the index treatment. * Active malignancy or a serious systemic disease substantially affecting body weight. * Pregnancy or breastfeeding at the index treatment. * Uncontrolled endocrine disease that may cause weight loss. * Missing baseline height or body weight measurements. * Recent participation in another intensive weight-loss program before the index treatment. * Concurrent use of another anti-obesity treatment that could substantially affect study outcomes. * Inability to reliably verify study data. GLP-1 Receptor Agonist Cohort: * Short-term GLP-1 receptor agonist use for an indication other than weight management. * Medication prescribed but never administered. Laparoscopic Sleeve Gastrectomy Cohort: * Sleeve gastrectomy performed concurrently with another bariatric procedure. * Sleeve gastrectomy performed for an indication other than primary obesity treatment.