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Bariatric Surgery vs Diet for Weight Loss

Waitlist Available
Led By Andres J Acosta, MD
Research Sponsored by Mayo Clinic
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Be older than 18 years old
Screening 3 weeks
Treatment Varies
Follow Up baseline, 12 weeks
Awards & highlights


This trial is testing whether the bile acid pathway reacts differently to weight loss from RYGB surgery than weight loss from caloric restriction.

Who is the study for?
This trial is for adults with severe obesity (BMI ≥ 40) who are healthy or have controlled health issues. Women must not be pregnant. Participants will either undergo Roux-En-Y Gastric Bypass surgery at the Mayo Clinic or follow a low-calorie diet if they're not having surgery. People with untreated psychiatric disorders, alcoholism, eating disorders, certain past surgeries, chronic gastrointestinal diseases, or conditions affecting study participation are excluded.Check my eligibility
What is being tested?
The study compares how the bile acid pathway responds to weight loss from two methods: Roux-En-Y Gastric Bypass surgery and a strict low-calorie diet alone. The goal is to see if there's a difference in this metabolic pathway depending on the weight loss strategy used.See study design
What are the potential side effects?
Potential side effects of gastric bypass include nutritional deficiencies, digestive problems like nausea and vomiting, and surgical complications such as infections. A low-calorie diet might cause fatigue, nutrient shortages if poorly managed, and psychological stress due to dietary restrictions.


Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~baseline, 12 weeks
This trial's timeline: 3 weeks for screening, Varies for treatment, and baseline, 12 weeks for reporting.

Treatment Details

Study Objectives

Outcome measures can provide a clearer picture of what you can expect from a treatment.
Primary outcome measures
Change in Bile Acid (BA) excretion

Trial Design

2Treatment groups
Active Control
Group I: Roux-En-Y Gastric Bypass (RYGB)Active Control1 Intervention
Participants will have elected to have RYGB surgery per standard of care.
Group II: Low-calorie DietActive Control1 Intervention
Participants will have a low-calorie diet prescribed by a registered dietitian.

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Who is running the clinical trial?

Mayo ClinicLead Sponsor
3,255 Previous Clinical Trials
3,835,385 Total Patients Enrolled
86 Trials studying Obesity
14,758 Patients Enrolled for Obesity
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)NIH
2,381 Previous Clinical Trials
4,315,081 Total Patients Enrolled
453 Trials studying Obesity
588,944 Patients Enrolled for Obesity
Andres J Acosta, MDPrincipal InvestigatorMayo Clinic

Media Library

Low-calorie Diet Clinical Trial Eligibility Overview. Trial Name: NCT03238794 — N/A
Obesity Research Study Groups: Roux-En-Y Gastric Bypass (RYGB), Low-calorie Diet
Obesity Clinical Trial 2023: Low-calorie Diet Highlights & Side Effects. Trial Name: NCT03238794 — N/A
Low-calorie Diet 2023 Treatment Timeline for Medical Study. Trial Name: NCT03238794 — N/A
~2 spots leftby Jan 2025