Bone Metabolism in 12-21 Year Olds Undergoing Glucagon Like Peptide (GLP)-1 Receptor Agonist Therapy

Inclusion Criteria: * • Adolescents and young adults with obesity 12-21 years old starting GLP-1 RA therapy (except for dulaglutide or exenatide) or followed with 'usual' care. * Diagnosis of obesity (BMI ≥ 95th percentile for age and sex). The FDA has approved the use of GLP-1 RAs (liraglutide and semaglutide) for adolescents ≥ 12 years old with BMI ≥ 95th percentile for age and sex, and tirzepatide for adults with obesity. Those in the GLP-1 RA arm must have demonstrated efforts at weight loss with 'usual' care, and consistent compliance with appointments and recommendations. * Participants must demonstrate sufficient maturity, psychological stability and cognitive capacity to recognize the significance of being on medical therapy and implement required behavioral changes * Patients taking orlistat as a precursor to GLP-1 RA therapy due to insurance requirements may be included given minimal effects on weight. * Use of the following contraceptive methods is permitted: Combine oral contraceptives (COCs); continuous oral progestin; Progestin-releasing intrauterine device (IUD); Progestin implant; transdermal patch. * Patients with celiac disease will be included if the condition is well controlled and they are on a gluten free diet with normal 25(OH)D levels confirmed by clinical labs within 3 months of enrollment in the study. If a patient does not have recent 25(OH)D results, we will add this to the screening labs. Exclusion Criteria: * • Current or previous history of p…