Impact of protein shakes on muscle preservation after weight loss surgery

Effect of Protein Supplementation on Fat Free Mass Preservation After Bariatric Surgery, a Randomized Double-blind Placebo-controlled Trial.

Not applicable Interventional Maasstad Hospital · NCT05570474

This study is testing if drinking a daily protein shake after weight loss surgery can help people keep their muscle mass during the first year after the surgery.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment266 (estimated)
Ages18 Years to 65 Years
SexAll
SponsorMaasstad Hospital Academic / other
Locations1 site (Rotterdam, Zuid Holland)
Trial IDNCT05570474 on ClinicalTrials.gov

What this trial studies

This double-blind randomized placebo-controlled trial examines how daily protein supplementation affects fat free mass loss in patients who have undergone Roux-en-Y gastric bypass surgery. The study aims to determine if a clear protein powder shake, consumed daily for six months post-surgery, can help maintain muscle mass during the first year after the procedure. Participants will be randomly assigned to receive either the protein shake or a placebo, allowing for a direct comparison of outcomes related to muscle preservation.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18-65 scheduled for laparoscopic Roux-en-Y gastric bypass with a BMI of 35 or higher and related severe comorbidities.

Not a fit: Patients who have had revisional bariatric surgery, are on a protein-restricted diet for medical reasons, or have certain muscular diseases may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could help bariatric surgery patients maintain muscle mass, reducing complications associated with protein deficiency.

How similar studies have performed: Previous studies have indicated that protein intake is crucial for preserving muscle mass during weight loss, suggesting that this approach may be effective.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* - Scheduled for a laparoscopic Roux-en-Y Gastric Bypass
* Age 18 - 65 years
* Body Mass Index ≥ 35 with the presence of severe comorbidity related to morbid obesity (diabetes mellitus type 2, obstructive sleep apnoea syndrome (OSAS), hypertension, etc.) or a BMI ≥ 40 with or without the presence of severe comorbidity related to morbid obesity
* Written informed consent

Exclusion Criteria:

* - Revisional bariatric surgery
* A protein-restricted diet for medical reasons
* Diagnosis of a (neuro-) muscular disease
* Inability to undergo MF-BIA (i.e. pregnancy, pacemaker)
* Allergy to any of the ingredients of either the protein or the placebo shake

Where this trial is running

Rotterdam, Zuid Holland

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Bariatric Surgery CandidateProtein DeficiencyMuscle Lossbariatric surgeryRYGBRoux-en-Y gastric bypassprotein supplementationfat free mass
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.