The PREBA Study: Effect of Preoperative Weight Loss With a 14-day Low-calorie Diet on Surgical Procedure and Outcomes in Patients Undergoing RYGB Surgery

January 2, 2025 updated by: Rijnstate Hospital

Bariatric guidelines recommend preoperative weight loss of 5% to reduce the risk of surgical complications. However, results in the literature on the improvement of surgical procedure and outcomes are still conflicting.

This study aims to evaluate the effect of preoperative weight loss by means of a 14-day low-calorie diet in bariatric patients on operative time, the ease of the Roux-en-Y gastric bypass (RYGB) procedure and long-term weight loss in a real-life experimental setting.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

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 (Estimated)

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.
80

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 Locations

  • Netherlands
    • Gelderland
      • Arnhem, Gelderland, Netherlands, 6811AD
        • Rijnstate 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:

  • Undergoing primary RYGB surgery (meeting all criteria + approval of surgeon)
  • Able to prepare the meal replacements at home

Exclusion Criteria:

  • Undergoing another bariatric procedure than primary RYGB.
  • Diabetes Mellitus

  • Contraindication for the usage of Modifast meal replacements:

    • Allergy or intolerance to any substance in the used meal replacements (Soy, milk, gluten, egg, peanuts, nuts and seeds)
    • Veganism
    • Kidney failure (GFR < 90 ml/min/1.73m2), liver failure or cardiac insufficiency
    • A heart attack (myocardial infarct) in the past twelve months
    • Cancer
    • Hypokalaemia: serum potassium level <3.4 mmol/l
    • Phenylketonuria & Porphyria

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: 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: Intervention group

Participants in the intervention group will follow a low-calorie diet during 14 days before undergoing surgery. The diet will consist of both meal replacements and regular foods.

For women, the diet provides ± 900 kcal, 50 grams of carbohydrates, 85 grams of protein, 30 grams of fat and 25 grams of fibres.

For men, the diet provides ± 1000 kcal, 55 grams of carbohydrates, 100 grams of protein, 30 grams of fat and 30 grams of fibres.
Other: 14-day Low Calorie Diet

Participants will be asked to:

  • Use 4 (women) or 5 (men) Modifast meal replacements per day.
  • Daily consume a minimum of 250 grams of (raw) vegetables without dressing.
  • Daily consume 100 grams of lean meat/fish/meat analogues.
  • Daily consume two spoons of liquid oil
  • Daily drink at least 2.0 litres of water, coffee or tea without added sugar or milk, bouillon or sugar-free drinks.
No Intervention: Control group
Participants in the control group can eat according to the standard nutritional advices provided by their dietitian. These advices are intended to educate participants on the recommended eating pattern after surgery.

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
Operative time of the RYGB procedure
Time Frame: surgery
Duration of the surgical procedure, retrieved from the electronic medical record
surgery

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Ease of the RYGB procedure
Time Frame: surgery

Ten aspects of the RYGB procedure will be scored on a 5-point Likert scale. The total score can range from 10 to 50, with 10 being the easiest.

The ten aspects include:

  • Exerting force on instruments (1=very low, 5= very high)
  • Difficulty of moving the liver (1=very easy, 5=very difficult)
  • Size of the liver (1=very small, 5= very large)
  • Size of omentum (1=very small, 5= very large)
  • Difficulty of approaching pouch (1=very easy, 5=very difficult)
  • Accessibility of Treitz ligament (1=very easy, 5=very difficult)
  • Difficulty of creating pouch (1=very easy, 5=very difficult)
  • Difficulty of measuring small intestine (1=very easy, 5=very difficult)
  • Difficulty of entero-entero connection (1=very easy, 5=very difficult)
  • Difficulty of abdominal wall hernia repair (1=very easy, 5=very difficult)
surgery
Appearance of the patient's liver
Time Frame: surgery
Includes four images of the liver in different stages (1= healthy, 2= fatty liver, 3= fatty liver with inflammation, 4= liver cirrhosis). Surgeons will be asked to choose the image that best matches the appearance of the patient's liver.
surgery
Post-operative weight loss
Time Frame: 4 weeks, 3, 6 months and 1, 2, 3, 4, 5 years after surgery
Body weight measurements to assess weight loss after surgery
4 weeks, 3, 6 months and 1, 2, 3, 4, 5 years after surgery

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Feasibility of the diet
Time Frame: During the 14-day intervention period
Feasibility will be assessed via questionnaires
During the 14-day intervention period
Compliance of the diet
Time Frame: During the 14-day intervention period
Compliance will be assessed via food records
During the 14-day intervention period
Complication rate
Time Frame: First 30 days post-surgery
All short term complications during the first 30 days will be recorded and classified according to the Clavien-Dindo classification
First 30 days post-surgery
Wound healing
Time Frame: 4 weeks
Degree of wound healing post-surgery will be checked based on appearance on a 5-point Likert scale.
4 weeks

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.
Rijnstate Hospital

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: Eric J Hazebroek, MD, PhD, Vitalys, part of Rijnstate hospital/Wageningen University

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 29, 2020

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.
June 22, 2022

Study Completion (Estimated)

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.
July 1, 2027

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).
June 12, 2020

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.
June 15, 2020

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.
June 16, 2020

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.
March 25, 2025

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.
January 2, 2025

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.
January 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

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.
  • NL70092.081.19

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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