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

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
54

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
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

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Norwegian University of Science and Technology

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
University of Copenhagen
University of Leeds
St. Olavs Hospital
Namsos Hospital
Norwegian University of Life Sciences

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • 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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 2, 2019

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2022

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2022

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 7, 2019

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 8, 2019

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 9, 2019

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 25, 2023

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 24, 2023

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2023

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant 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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