Protein-collagen supplementation plus resistance exercise to prevent muscle loss after bariatric surgery

Preventing Muscle Loss in the Early Postoperative Period of Bariatric Surgery With a Combination of Whey Protein, Hydrolyzed Collagen, and Resistance Exercise: A Prospective, Randomized, Controlled Clinical Study

Not applicable Interventional Medipol University · NCT07303543

This trial will test whether adding collagen to standard whey protein and doing resistance exercise helps people who have bariatric surgery keep muscle and change fat mass.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment35 (estimated)
Ages20 Years to 50 Years
SexAll
SponsorMedipol University Academic / other
Locations1 site (Istanbul, Fatih)
Trial IDNCT07303543 on ClinicalTrials.gov

What this trial studies

Adults undergoing bariatric surgery will be assigned to one of four groups that all receive standard post-surgery nutrition and vitamin/mineral support but differ by supplementation and exercise: whey only, whey plus collagen with exercise, whey plus collagen without exercise, and whey plus exercise without collagen. Interventions include a whey protein supplement, hydrolyzed collagen supplement, and a supervised resistance exercise program where applicable. Muscle mass and fat mass will be measured before and after the intervention period to compare the independent and combined effects of collagen and resistance training. The study aims to determine whether adding collagen provides extra muscle-preserving benefit beyond whey protein and exercise in the early postoperative period.

Who should consider this trial

Good fit: Adults aged 20–50 with BMI 35 to under 60 kg/m2 who are undergoing bariatric surgery, are not pregnant or menopausal, are not using statins, and have no exercise restrictions are the intended participants.

Not a fit: People older than 50, postmenopausal individuals, those with inflammatory bowel disease, advanced psychiatric illness, cancer, kidney failure, statin use, pregnancy, substance addiction, exercise restrictions, or who are professional athletes or already do more than 60 minutes of regular structured exercise per week are unlikely to match the trial population and may not benefit.

Why it matters

Potential benefit: If successful, adding collagen and resistance exercise to standard whey protein could help preserve skeletal muscle after bariatric surgery, supporting better physical function and weight maintenance.

How similar studies have performed: Whey protein is commonly used postoperatively and small studies suggest collagen plus resistance exercise might support muscle, but combined evidence specifically after bariatric surgery is limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Being between 20-50 years old
* Body mass index; 35 ≤ BMI\< 60 kg/m2
* Not being pregnant
* Not being addicted to alcohol and drugs
* Not having entered menopause
* No exercise restrictions

Exclusion Criteria:

* Having at least one of the following inflammatory bowel diseases, upper gastrointestinal bleeding, advanced psychiatric diseases, cancer, and kidney failure.
* using statins
* be pregnant
* Being addicted to alcohol and drugs
* to have entered menopause
* Having exercise restrictions
* Becoming a professional athlete
* Having done more than 60 minutes of regular and structured exercise per week in the last year

Where this trial is running

Istanbul, Fatih

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 SurgeryMuscle LossCollagenResistance exerciseWhey proteinMuscle loss
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.