GLP-1 Receptor Agonist Use and Sarcopenia in Obese Individuals Without Diabetes

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and dual GLP-1/GIP agonists such as semaglutide and tirzepatide produce marked weight loss in people with obesity, with reported reductions of about 15-20%. Rapid weight loss may reduce not only fat mass but also lean body mass and skeletal muscle mass, raising concern about sarcopenia and sarcopenic obesity. Evidence in non-diabetic obese individuals is limited and inconsistent. This prospective descriptive study will assess muscle mass, muscle strength, physical performance and sarcopenia risk in non-diabetic obese adults starting GLP-1 RA therapy, at baseline and at month 3, and will examine how weight loss relates to changes in body composition.

Inclusion Criteria: * Age 18 years or older * Diagnosis of obesity (BMI \>30 kg/m²) * Currently using a GLP-1 RA * No hearing, speech or cognitive impairment * Not receiving treatment for major depressive disorder and not using antidepressants * Verbal consent to participate Exclusion Criteria: * Diagnosis of diabetes * History of chronic kidney failure, chronic liver disease, decompensated heart failure or malignancy * Pregnancy or breastfeeding * Walking impairment * Not meeting inclusion criteria or unwilling to participate