NCT07115069 · Vanderbilt University Medical Center
Comparison of Body Composition Changes With Weight Loss Interventions
(REFORM)
What this study is about
This study is being done to compare the effects of a newer class of weight loss medications to weight loss surgery on the body's muscle, metabolism, and side effects over time. People with severe obesity often lose weight using either medications like GLP-1 receptor agonists (such as semaglutide or tirzepatide) or by having bariatric surgery, such as gastric bypass.
View original scientific description
This study is being done to compare the effects of a newer class of weight loss medications to weight loss surgery on the body's muscle, metabolism, and side effects over time. People with severe obesity often lose weight using either medications like GLP-1 receptor agonists (such as semaglutide or tirzepatide) or by having bariatric surgery, such as gastric bypass. While both approaches can lead to weight loss, they may affect the body in different ways. The investigators are inviting adult patients who are planning to either start one of these weight loss medications or undergo gastric bypass surgery to join this study. Participants will be asked to complete four body composition scans (called DXA scans) over the course of a year-at the beginning of the study and again at 3, 6, and 12 months. These scans will help us measure changes in fat and muscle. Participants will also complete surveys and provide information on side effects, such as nausea or fatigue, that may affect their eating or activity levels. The investigators' goal is to better understand how different weight loss treatments impact not just weight, but also muscle mass, energy levels, and side effects. This information may help doctors and patients choose the most appropriate treatment in the future.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- BMI ≥35 and ≤60
- Primary weight loss surgery (gastric bypass), or
- Medical weight loss with GLP1RAs (Semaglutide or Tirzepatide)
Exclusion criteria
- Revisional gastric bypass (e.g. sleeve to bypass),
- \<3 months of continuous use of GLP1RA,
- Type 1 Diabetes,
- Myocardial Infarction,
- Unstable Angina or Heart Failure,
- Solid organ transplantation,
- Systemic glucocorticoid prior 28 days,
- Uncontrolled Hypertension, (Systolic \> 150, Diastolic \> 90)
- Untreated Hyperthyroidism
- Chronic Kidney Disease (EGFR \< 60).
Where
- Nashville, Tennessee
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Oct 21, 2025 · Source of record for eligibility and locations