Effect of Diet Versus Sleeve Gastrectomy and Gastric Bypass on Appetite (DISGAP)

July 24, 2023 updated by: Norwegian University of Science and Technology

Effects of Diet-induced Weight Loss Versus Sleeve Gastrectomy and Gastric Bypass on Homeostatic and Hedonic Appetite Markers and Gut Microbiota

The biggest challenge in obesity management is maintaining weight loss in the long-term. Currently, bariatric surgery is the most effective treatment, leading to sustained weight loss that is not yet achievable with lifestyle intervention (e.g. diet). The reasons behind its success is still not clearly understood, but beneficial changes in the homeostatic and hedonic appetite systems (the two major physiological regulators of appetite), along with the microbiome (known to have a mediatory effect on appetite) have been shown to occur after bariatric surgery. These alterations are in opposition to what is seen after diet-induced weight loss. Today, the component of appetite regulation that drives bariatric surgeys' long-term success is still unknown. By comparing a lifestyle and surgical intervention in parallel, the investigators can observe the impact of a similar magnitude of weight loss on these three domains of appetite regulation simultaneously, thereby illuminating the mechanisms behind bariatric surgerys' success.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

54

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Norway
      • Namsos, Norway
        • Namsos Hospital
      • Trondheim, Norway
        • St. Olavs Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • scheduled for bariatric surgery
  • patient in obesity clinic
  • Body mass index (BMI) 35-55

Exclusion Criteria:

  • Currently taking medication known to affect energy metabolism or appetite
  • Current cancer diagnosis
  • Substance abuse
  • Enrolled in another obesity treatment
  • Eating disorders
  • pre-existing endocrine disorders (e.g. diabetes) will not be excluded, but final analysis will controlled for these conditions

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: VLED group
Participants will undergo a 10-week VLED.
Dietary supplement: VLED group
10-week weight loss period with total meal replacement, consisting of 750 kcal/day. Measurements will be taken at baseline (before diet start), 10 weeks after intervention start (Wk11), and at 1 year.
Other Names:
  • very-low-energy-diet
Experimental: Sleeve Gastrectomy group
Participants will undergo standard clinical practice prior to surgery.
Dietary supplement: VLED group
10-week weight loss period with total meal replacement, consisting of 750 kcal/day. Measurements will be taken at baseline (before diet start), 10 weeks after intervention start (Wk11), and at 1 year.
Other Names:
  • very-low-energy-diet
Procedure: Sleeve Gastrectomy group
Standard clinical practice with 2-week diet consisting of 750 kcal/day prior to surgery. The pre- and post-surgical diet of this group will be matched with the VLED group in macro- and micronutrient composition. Measurements will be taken at baseline (before diet start), 10 weeks after intervention start (Wk11), and 1 year after surgery (sleeve gastrectomy)
Experimental: Gatric Bypass group
Participants will undergo standard clinical practice prior to surgery.
Dietary supplement: VLED group
10-week weight loss period with total meal replacement, consisting of 750 kcal/day. Measurements will be taken at baseline (before diet start), 10 weeks after intervention start (Wk11), and at 1 year.
Other Names:
  • very-low-energy-diet
Procedure: Gastric Bypass group
Standard clinical practice with 2-week diet consisting of 750 kcal/day prior to surgery. The pre- and post-surgical diet of this group will be matched with the VLED group in macro- and micronutrient composition. Measurements will be taken at baseline (before diet start), 10 weeks after intervention start (Wk11), and 1 year after surgery (gastric bypass)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postprandial blood plasma concentration of Glucagon-like peptide-1 (GLP-1, satiety hormone)
Time Frame: Week 11
Blood samples will be collected at fasting, and then every 30 minutes after a standardized test meal up to 150 minutes. A radioimmunoassay method will be used to measure the concentration of total GLP-1. This method measures antigen concentrations by the use of antibodies.
Week 11

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Norwegian University of Science and Technology

Collaborators

University of Copenhagen
University of Leeds
St. Olavs Hospital
Namsos Hospital
Norwegian University of Life Sciences

Investigators

  • Principal Investigator: Catia Martins, PhD, Norwegian University of Science and Technology

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 2, 2019

Primary Completion (Actual)

December 31, 2022

Study Completion (Actual)

December 31, 2022

Study Registration Dates

First Submitted

August 7, 2019

First Submitted That Met QC Criteria

August 8, 2019

First Posted (Actual)

August 9, 2019

Study Record Updates

Last Update Posted (Actual)

July 25, 2023

Last Update Submitted That Met QC Criteria

July 24, 2023

Last Verified

July 1, 2023

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • 2019/252

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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