Bariatric Surgery vs Diet for Weight Loss

Overseen By Andres J Acosta, MD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Mayo Clinic

Must not be taking: Orlistat, Phentermine

Disqualifiers: Abdominal surgery, Chronic GI diseases, Psychiatric dysfunction, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 1

Duration: 12 weeks

21 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

It is unknown whether the bile acid pathway reacts differently to weight loss resulting from Roux-En-Y Gastric Bypass (RYGB) surgery than weight loss resulting from caloric restriction alone.

Will I have to stop taking my current medications?

Participants must avoid taking any new over-the-counter or prescription medications or herbal supplements that have not been reviewed and approved by the physician or study coordinator. The protocol does not specify if you need to stop your current medications, but you should discuss them with the study team.

Is Roux-en-Y gastric bypass generally safe for weight loss?

Roux-en-Y gastric bypass (RYGB) is generally considered safe and effective for weight loss, even in patients with a high body mass index (BMI). However, there can be complications, such as issues with orogastric tubes during surgery and potential nutritional problems if additional procedures are needed. ^{1 2 3 4 5}

How does Roux-En-Y Gastric Bypass differ from other weight loss treatments?

Roux-En-Y Gastric Bypass is unique because it not only restricts food intake but also reduces nutrient absorption and alters hormones that affect hunger, leading to more effective and sustained weight loss compared to other treatments like gastric banding. ^{6 7 8 9 10}

What data supports the effectiveness of the treatment Low-calorie Diet, Roux-En-Y Gastric Bypass for weight loss?

Research shows that Roux-En-Y Gastric Bypass surgery leads to significant weight loss by reducing food intake and nutrient absorption. Studies indicate that patients experience a dramatic decrease in calorie intake and maintain weight loss over time, with successful outcomes linked to higher protein intake. ^{9 11 12 13 14}

Who Is on the Research Team?

Andres Acosta

Principal Investigator

Mayo Clinic

Are You a Good Fit for This Trial?

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.

Inclusion Criteria

Women of childbearing potential will have negative pregnancy tests within 48 hours of enrolment

BMI: ≥ 40

The non-RYGB participants (BMI ≥40) will be otherwise healthy individuals with no unstable psychiatric disease and no unstable cardiac, pulmonary, gastrointestinal, hepatic, renal, hematological, neurological, or endocrine disorders.

Exclusion Criteria

If you have significant mental health issues like anxiety, depression, substance abuse, or eating disorders, you may be excluded from the study. A screening test will be used to check for these issues. If any problems are found, you will be referred to your primary care doctor for further evaluation and care. Additionally, your alcohol consumption will be assessed using a questionnaire. If your score is above the recommended limits, it will be reviewed by the study team to determine if you are eligible for the study.

History of abdominal surgery including cholecystectomy and other than appendectomy, Caesarian section or tubal ligation

Any acute or chronic condition or other disease that, in the opinion of the Investigator, would limit the subject's ability to complete and/or participate in this clinical study.Participant activities: If recruited for the investigation participants will be asked to refrain from donating blood; refrain from participating in other research studies; avoid taking any additional over the counter or prescription medications or herbal supplements that have not been reviewed and approved by the physician or the study coordinator until the study has been completed

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Baseline Testing

Participants undergo baseline testing including stool collection and blood sampling after an overnight fast

1 day

1 visit (in-person)

Treatment

Participants undergo RYGB surgery or follow a low-calorie diet until 7% body weight loss is achieved

12 weeks

Follow-up

Participants are monitored for changes in bile acid excretion and other health metrics

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Low-calorie Diet
• Roux-En-Y Gastric Bypass

Trial Overview 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.

How Is the Trial Designed?

Group I: Roux-En-Y Gastric Bypass (RYGB) Active Control 1 Intervention

Participants will have elected to have RYGB surgery per standard of care.

Group II: Low-calorie Diet Active Control 1 Intervention

Participants will have a low-calorie diet prescribed by a registered dietitian.

Who Is Running the Clinical Trial?

Mayo Clinic

Lead Sponsor

Trials

3,427

Recruited

3,221,000+

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Collaborator

Trials

2,513

Recruited

4,366,000+

Published Research Related to This Trial

Bariatric surgery, such as Roux-en-Y gastric bypass and biliopancreatic diversion, is effective for long-term weight loss and reducing health risks in morbidly obese individuals, but it can lead to serious nutritional complications that may require revisional surgery.

In a study of four patients who underwent revisional surgery due to complications, one patient died, highlighting that while revision surgery is rare, it carries increased risks and can involve different surgical approaches depending on the patient's condition.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Revisional surgery in severe nutritional complications after bariatric surgical procedures: report of four cases from a single institution and review of the literature. Braga, JGR., Concon, MM., Lima, AP., et al.[2021]

In a study of 213 type 2 diabetes patients with a BMI of 25 to 32.5 kg/m2, Roux-en-Y gastric bypass (RYGB) was found to be more effective than medical treatment in achieving significant metabolic improvements, with 23.9% of RYGB patients meeting the triple endpoint compared to only 7.0% in the medical group.

However, RYGB was associated with a higher rate of complications (36 vs. 22), highlighting the need to weigh the benefits of improved metabolic outcomes against the risks of surgical complications when considering treatment options for patients with lower BMI.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Two-year outcomes of Roux-en-Y gastric bypass vs medical treatment in type 2 diabetes with a body mass index lower than 32.5 kg/m2: a multicenter propensity score-matched analysis. Ling, J., Tang, H., Meng, H., et al.[2022]

Citations

1. United States pubmed.ncbi.nlm.nih.gov

Preoperative very low-calorie diet and operative outcome after laparoscopic gastric bypass: a randomized multicenter study. [2011]

2. United States pubmed.ncbi.nlm.nih.gov

Preoperative and postoperative assessment of nutrient intakes in patients who have undergone gastric bypass surgery. [2019]

3. Brazil pubmed.ncbi.nlm.nih.gov

Revisional surgery in severe nutritional complications after bariatric surgical procedures: report of four cases from a single institution and review of the literature. [2021]

4. United States pubmed.ncbi.nlm.nih.gov

Can response to dietary restriction predict weight loss after Roux-en-Y gastroplasty? [2018]

5. Korea (South) pubmed.ncbi.nlm.nih.gov

Macro- and Micro-nutrient Intake Adequacy in Gastric Bypass Patients after 24 Months: a Cross-sectional Study. [2023]

6. England pubmed.ncbi.nlm.nih.gov

Impact of body weight, low energy diet and gastric bypass on drug bioavailability, cardiovascular risk factors and metabolic biomarkers: protocol for an open, non-randomised, three-armed single centre study (COCKTAIL). [2019]

7. Italy pubmed.ncbi.nlm.nih.gov

Two-year outcomes of Roux-en-Y gastric bypass vs medical treatment in type 2 diabetes with a body mass index lower than 32.5 kg/m2: a multicenter propensity score-matched analysis. [2022]

8. United States pubmed.ncbi.nlm.nih.gov

Short-term results of laparoscopic gastric bypass in patients with BMI > or = 60. [2019]

9. United States pubmed.ncbi.nlm.nih.gov

Orogastric tube complications in laparoscopic Roux-en-Y gastric bypass. [2010]

10. United States pubmed.ncbi.nlm.nih.gov

Distal small bowel bypass for weight regain after gastric bypass: safety and efficacy threshold occurs at [2022]

11. United States pubmed.ncbi.nlm.nih.gov

Roux-En-Y Gastric Bypass and Sleeve Gastrectomy Does Not Affect Food Preferences When Assessed by an Ad libitum Buffet Meal. [2022]

12. England pubmed.ncbi.nlm.nih.gov

Obese patients after gastric bypass surgery have lower brain-hedonic responses to food than after gastric banding. [2022]

13. United States pubmed.ncbi.nlm.nih.gov

Changes in taste perception and eating behavior after bariatric surgery-induced weight loss in women. [2021]

14. United States pubmed.ncbi.nlm.nih.gov

Patient factors associated with undergoing laparoscopic adjustable gastric banding vs Roux-en-Y gastric bypass for weight loss. [2021]