Active — Not RecruitingNot Applicable

Comparison of Body Composition Changes With Weight Loss Interventions

United States60 participantsStarted 2025-08-09

Plain-language summary

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

Age range

21 Years – 65 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

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, * Stroke * Solid organ transplantation, * Systemic glucocorticoid prior 28 days, * Uncontrolled Hypertension, (Systolic \> 150, Diastolic \> 90) * Untreated Hyperthyroidism * Chronic Kidney Disease (EGFR \< 60).

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Skeletal Muscle Loss

Timeframe: 6 months

Skeletal Muscle Loss

Timeframe: 12 months

Patient Assessment of Upper Gastrointestinal Disorders Symptoms Questionnaire

Timeframe: 6 months

Patient Assessment of Upper Gastrointestinal Disorders Symptoms Questionnaire

Timeframe: 12 months

Trial details

NCT IDNCT07115069

SponsorVanderbilt University Medical Center

Sponsor typeOTHER

Study typeOBSERVATIONAL

Primary completion2027-06

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