Daily protein plus weekly resistance training to prevent muscle loss after bariatric surgery

Effectiveness of Protein SupplementatIon Combined With Resistance Exercise Training to Counteract Disproportional Fat-Free Mass Loss Following Metabolic-Bariatric Surgery: The ENRICHED Study

Not applicable Interventional Radboud University Medical Center · NCT07156552

The trial will test whether taking a daily protein supplement and doing one supervised resistance workout each week helps people having bariatric surgery keep their muscle mass.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment400 (estimated)
Ages18 Years and up
SexAll
SponsorRadboud University Medical Center Academic / other
Locations2 sites (Amsterdam and 1 other locations)
Trial IDNCT07156552 on ClinicalTrials.gov

What this trial studies

This randomized interventional study will compare usual postoperative care to usual care plus daily protein supplementation and one supervised resistance training session per week in patients undergoing Roux-en-Y gastric bypass or sleeve gastrectomy. Participants treated at participating centers will be randomly assigned to the two groups and followed for changes in fat-free mass and related outcomes. The study targets prevention of excessive muscle loss, a complication reported in about 20% of bariatric patients. While resistance training and protein intake are each known to support muscle mass, the combined effect in the bariatric population will be measured.

Who should consider this trial

Good fit: Ideal candidates are adults scheduled for Roux-en-Y gastric bypass or sleeve gastrectomy who are enrolled in the Nederlandse Obesitas Kliniek (NOK) care program and able to follow supplement and weekly supervised exercise procedures.

Not a fit: Patients with milk-protein allergy or lactose intolerance, diagnosed renal insufficiency, or intestinal diseases that impair protein absorption — and those unable to attend weekly supervised sessions — may not benefit or may be excluded.

Why it matters

Potential benefit: If successful, the approach could help patients retain muscle mass and strength after bariatric surgery, improving recovery and long-term function.

How similar studies have performed: Previous studies show resistance training and increased protein intake each help preserve or build muscle, but randomized data on the combined intervention specifically after bariatric surgery are limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* A scheduled metabolic-bariatric surgery (i.e. RYGB or Sleeve Gastrectomy)
* Participation in the NOK care program
* Able to understand and perform the study procedures

Exclusion Criteria:

* Allergic or sensitive for milk proteins, or lactose intolerant
* Diagnosed renal insufficiency
* Diagnosed intestinal diseases influencing the uptake of protein (i.e. active inflammatory bowel disease

Where this trial is running

Amsterdam and 1 other locations

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 SurgeryFat Free MassMetabolic-Bariatric SurgerySleeve GastrectomyRoux-en Y Gastric BypassProtein SupplementationResistance Training
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.