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Bariatric SurgeryENRICHEDNCT07156552

Protein Supplementation and Resistance Training to Prevent Fat-Free Mass Loss Following Metabolic-Bariatric Surgery

A study testing Resistance exercise training and protein supplementation in people with Bariatric Surgery and Fat Free Mass, run by Radboud University Medical Center at 2 sites in Netherlands.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The goal of this clinical trial is to investigate the effects of daily protein supplementation and participation in a weekly supervised resistance training program on the prevention of excessive muscle mass loss following bariatric surgery. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Bariatric Surgery, Fat Free Mass
What is being tested?
Resistance exercise training and protein supplementation
Could I receive a placebo?
No, everyone receives an active treatment
How many people
400 participants
Where
2 sitesNetherlands
Study dates
20 Jun 2025to 31 Dec 2027
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • 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

Who cannot join

  • 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

Trial locations and contacts

2 sites in 1 country. Contact the study team or a site near you to ask about taking part.

J. H.M. Karregat, Dr. contact

+31653461919

jan.karregat@radboudumc.nl

B. M. de Roos, Drs. contact

+31681363125

bente.deroos@radboudumc.nl

Netherlands2 sites, 2 recruiting

  • Nederlandse Obesitas Kliniek

    Amsterdam, 1043 DS

    Puck S. van den Hooff, drs, +31649653657, pvandenhooff@obesitaskliniek.nl

    Not yet recruiting

  • Nederlandse Obesitas Kliniek

    Nieuwegein, 3431

    L. Y. Yeh, drs, +31618298507, yyeh@obesitaskliniek.nl

    Recruiting

Other trials in Netherlands

About this study

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

The goal of this clinical trial is to investigate the effects of daily protein supplementation and participation in a weekly supervised resistance training program on the prevention of excessive muscle mass loss following bariatric surgery. Patients treated at one of the participating centers will be invited to participate and will be randomly assigned to one of two groups.

Participants in group 1 will receive standard postoperative care as currently provided. Participants in group 2 will also receive standard care, but in addition, they will be asked to consume extra protein daily and take part in a supervised resistance training session once a week.

Previous research has shown that approximately one in five patients undergoing bariatric surgery experiences excessive muscle loss after the surgery. It is known that resistance training and protein intake can help maintain and even improve muscle mass. However, limited research has been conducted on the combined effects of protein supplementation and resistance training in patients after bariatric surgery. Therefore, the aim of this trial is to determine whether participants receiving the additional intervention experience less muscle mass loss compared to those receiving standard care alone.

Being tested
Resistance exercise training and protein supplementation
Keywords
Metabolic-Bariatric Surgery, Bariatric Surgery, Sleeve Gastrectomy, Roux-en Y Gastric Bypass, Protein Supplementation, Resistance Training

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Resistance exercise training and protein supplementationBehavioural

    The intervention consists of two components:

    1. Resistance Exercise Training Participants will engage in a 24-week resistance training program. This program includes one supervised session per week supervised by a qualified kinesiologist, complemented by two to three additional unsupervised sessions per week performed at home.
    2. Protein Supplementation

    Participants will receive daily protein supplements for a total duration of 12 weeks. The dosage will be progressively increased:

    • 20 grams per day during weeks 1-4
    • 40 grams per day during weeks 5-8
    • 60 grams per day during weeks 9-12 After the 12-week supplementation period, participants will receive additional dietary counseling sessions with a dietitian. These sessions aim to support the maintenance of adequate protein intake through dietary intake.
Study groups in NCT07156552
Study groupRoleWhat they receive
Control group - Standard careNo interventionNot described
Intervention group - Enriched careExperimentalNot described
Receives: Behavioral: Resistance exercise training and protein supplementation

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Prevalence of Fat-free mass loss/Total weight loss >30%

    Measured: From enrollment to 3 months post-surgery

Secondary outcomes (16)

  1. Weight (kg)

    Measured: From enrollment to 12 months post-surgery

  2. Body Mass Index (kg/m2)

    Measured: From enrollment to 12 months post-surgery

  3. Body composition (fat-mass/fat-free mass) (kg)

    Measured: From enrollment to 12 months post-surgery

  4. Waist circumference (cm)

    Measured: From enrollment to 12 months post-surgery

  5. Blood pressure (mmHg)

    Measured: From enrollment to 12 months post-surgery

  6. Quadriceps isometric strength (kg)

    Measured: From enrollment to 12 months post-surgery

  7. Quadriceps isometric power (Watt)

    Measured: From enrollment to 12 months post-surgery

  8. Handgrip strength (kg)

    Measured: From enrollment to 12 months post-surgery

  9. Short Physical Performance Battery (SPPB) score (scale 1-12 points)

    Based on a balance test (0-4 points), a gait speed test (0-4 points), and a repeated chair stand (0-4 points)

    Measured: From enrollment to 12 months post-surgery

  10. VO2max (L/min)

    Assessment using the Astrand-Rhyming six minute cycle ergometer test

    Measured: From enrollment to 12 months post-surgery

  11. Incidence of gastrointestinal symptoms

    Assessment using the Gastrointestinal Symptom Rating Scale (GSRS) questionnaire

    Measured: From enrollment to 12 months post-surgery

  12. Difference in Health-Related Quality of Life (HRQoL)

    Assessment using the BODY-Q questionnaire

    Measured: From enrollment to 12 months post-surgery

  13. Healthcare consumption (costs)

    Measured: From enrollment to 12 months post-surgery

  14. Blood marker HOMA-IR

    Based on fasted insulin (microU/mL) and glucose (mmol/L) levels

    Measured: From enrollment to 12 months post-surgery

  15. Blood marker high-sensitivity C-Reactive Protein (hs-CRP) (mg/L)

    Measured: From enrollment to 12 months post-surgery

  16. Blood marker lipid profile

    Based on HDL-cholesterol (mg/dL), LDL-cholesterol (mg/dL), and triglycerides (mg/dL)

    Measured: From enrollment to 12 months post-surgery

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted5 Sep 2025
  2. Study start20 Jun 2025
  3. Primary completion30 May 2027 (estimated)
  4. Study completion31 Dec 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
400 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07156552
Sponsor's protocol ID
NL87367.091.24
Acronym
ENRICHED
Status last verified
Aug 2026
First submitted
22 Jul 2025
Last updated
11 Aug 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • de Roos BM, Yeh LY, van den Hooff PS, Nuijten MAH, Twisk JWR, Liem RSL, van Acker GJD, Severens JL, Kambic T, Serlie MJM, Monpellier VM, Eijsvogels TMH, Hopman MTE, Karregat JHM. Effectiveness of protein supplementation combined with resistance training to counteract disproportional fat-free mass loss following metabolic bariatric surgery: rationale and design of the ENRICHED randomised controlled trial. BMJ Open. 2025 Dec 29;15(12):e108346. doi: 10.1136/bmjopen-2025-108346.

    PubMed 41469063

Questions about this trial

What is this clinical trial studying?

A study testing Resistance exercise training and protein supplementation in people with Bariatric Surgery and Fat Free Mass, run by Radboud University Medical Center at 2 sites in Netherlands.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 11 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in Netherlands. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact J. H.M. Karregat, Dr. (+31653461919, jan.karregat@radboudumc.nl), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Prevalence of Fat-free mass loss/Total weight loss >30% (time frame: From enrollment to 3 months post-surgery). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07156552, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Aug 2026.

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