Obesity & OverweightNCT07809152
Collagen Supplements and Post-MBS Muscle Mass/Body Image
An observational study of Obesity & Overweight and Collagen Protein, run by Mudanya University at 1 site in Turkey (Türkiye).
Trial summary
This prospective, observational cohort study aims to evaluate whether the use of collagen-containing supplements is associated with differences in muscle mass, body composition, and body image among patients who have undergone sleeve gastrectomy (SG). Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Obesity & Overweight, Collagen Protein, Bariatric Surgery
- What is being tested?
- Collagen-containing supplement
- How many people
- 52 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Jul 2026to 10 Feb 2027
- Phase
- Observational
- 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 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Adult patients aged 18-65 years who underwent sleeve gastrectomy and are under routine postoperative follow-up at the General Surgery outpatient clinic of a private hospital in Bursa, Türkiye. Eligible patients meet current ASMBS/IFSO criteria for metabolic and bariatric surgery (BMI ≥ 35 kg/m², or BMI 30-34.9 kg/m² with an obesity-related metabolic comorbidity). Participants are naturally grouped according to their own preference to use or not use a collagen-containing supplement following surgery.
Who may be able to join
- Patients with a BMI ≥ 35 kg/m², regardless of the presence of comorbidities
- Patients with a BMI of 30-34.9 kg/m² who have an obesity-related metabolic disease and are considered eligible for surgical treatment
- Patients who have undergone metabolic and bariatric surgery (MBS) in accordance with current ASMBS/IFSO guidelines (Eisenberg et al., 2022)
- Patients under regular postoperative follow-up
- Age 18-65 years
Who cannot join
- Inflammatory bowel disease
- History of upper gastrointestinal bleeding
- Severe psychiatric disorders
- Active cancer diagnosis
- Pregnancy or breastfeeding
- Alcohol or substance dependence
- Physical limitations preventing participation in exercise
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Emre Şen, Master's degree graduate contact
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Yıldırım Doruk Hastanesi
Bursa, Yıldırım
05393919700, seher.sen@mudanya.edu.tr
About this study
Official title: Relationship Between Collagen-Containing Supplement Use and Muscle Mass and Body Image Following Metabolic and Bariatric Surgery: A Prospective Observational Study
This prospective, observational cohort study aims to evaluate whether the use of collagen-containing supplements is associated with differences in muscle mass, body composition, and body image among patients who have undergone sleeve gastrectomy (SG). The study will be conducted at the General Surgery outpatient clinic of a private hospital in Bursa, Türkiye, between May 2026 and March 2027, and will enroll adult patients (aged 18-65 years) who meet current ASMBS/IFSO eligibility criteria for metabolic and bariatric surgery.
Participants will be naturally allocated into two observational groups based on their own choice to use or not use collagen-containing supplements; no supplement will be provided or recommended by the study team, and no intervention will be made to participants' standard clinical care. All patients will be followed according to routine clinical practice preoperatively and at 2 weeks, 1 month, 3 months, and 6 months postoperatively.
Read more
Primary outcome measures include anthropometric parameters (body weight, BMI, fat mass, fat mass percentage, fat-free mass, muscle mass, percentage of weight loss, percentage of excess weight loss, waist and hip circumference) assessed via bioelectrical impedance analysis (Tanita MC-780 MA), and body image assessed using the Turkish-validated Body Shape Questionnaire (BSQ). Secondary outcomes include biochemical parameters, comorbidities, and macronutrient intake data obtained from 3-day dietary records analyzed using the BEBİS nutrition software.
The study hypothesizes that patients using collagen-containing supplements will show significant differences in muscle mass and body composition parameters compared with non-users, and that supplement use will be significantly associated with BSQ scores. A sample size of approximately 52 participants per group was calculated using G*Power 3.1 (one-way ANOVA, Cohen's f = 0.25, α = 0.05, power = 0.80).
- Conditions
- Obesity & Overweight, Collagen Protein, Bariatric Surgery, Metabolic and Bariatric Surgery, Body Composition, Muscle Composition
- Being tested
- Collagen-containing supplement
- Keywords
- Bariatric Surgery, Collagen Supplementation, Muscle Mass, Body Composition
- Medical subject headings
- Obesity, Overweight
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Collagen-containing supplementDietary supplement
Collagen-containing supplement products used at the participants' own discretion following sleeve gastrectomy. The type of product, daily dosage, and duration of use were self-reported by participants
| Study group | Role | What they receive |
|---|---|---|
| 1. Grup | Group/Cohort Label: Collagen Supplement Users (Kolajen Kullananlar) Description: Participants who, based on their own preference, use a collagen-containing supplement product following sleeve gastrectomy, without any intervention or recommendation from the study team. Receives: Dietary Supplement: Collagen-containing supplement | |
| 2. Grup | Group/Cohort Label: Non-Users of Collagen Supplement (Kolajen Kullanmayanlar) Description: Participants who do not use any collagen-containing supplement product following sleeve gastrectomy, followed under routine clinical care. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Body Weight
Body weight (kg) measured using a Tanita MC-780 MA device.
Measured: Preoperative, and postoperative 2 weeks, 1 month, 3 months, and 6 months
Change in Body Shape Questionnaire (BSQ) Score
Body image concerns were assessed using the Body Shape Questionnaire (BSQ-34), a validated instrument for the Turkish population. This 34-item self-report scale evaluates weight-related concerns and dissatisfaction with body shape over the preceding four weeks. Each item is scored from 1 (never) to 6 (always), with a total score range of 34 to 204. Higher scores indicate greater dissatisfaction with body shape, i.e., a worse outcome.
Measured: Preoperative and postoperative 6 months
Change in Body Mass Index (BMI)
BMI calculated as body weight (kg) divided by height squared (m²).
Measured: Preoperative, and postoperative 2 weeks, 1 month, 3 months, and 6 months
Percentage of Total Weight Loss (%TWL)
Calculated as (preoperative weight - postoperative weight) / preoperative weight × 100.
Measured: Postoperative and 6 months
Percentage of Excess Weight Loss (%EWL)
Calculated as (preoperative weight - postoperative weight) / (preoperative weight - ideal weight) × 100. Ideal body weight was calculated assuming a BMI of 25 kg/m².
Measured: Postoperative and 6 months
Change in Fat Mass
Fat mass (kg) assessed by multi-frequency bioelectrical impedance analysis (BIA) using a Tanita MC-780 MA device.
Measured: Preoperative, and postoperative 2 weeks, 1 month, 3 months, and 6 months
Change in Fat Mass Percentage
Fat mass expressed as a percentage of total body weight, assessed by bioelectrical impedance analysis (BIA) using a Tanita MC-780 MA device.
Measured: Preoperative, and postoperative 2 weeks, 1 month, 3 months, and 6 months
Change in Muscle Mass
Muscle mass (kg) assessed by bioelectrical impedance analysis (BIA) using a Tanita MC-780 MA device.
Measured: Preoperative, and postoperative 2 weeks, 1 month, 3 months, and 6 months
Change in Muscle Mass Percentage
Muscle mass expressed as a percentage of total body weight, assessed by bioelectrical impedance analysis (BIA) using a Tanita MC-780 MA device.
Measured: Preoperative, and postoperative 2 weeks, 1 month, 3 months, and 6 months
Secondary outcomes (21)
Change in Fasting Blood Glucose
Fasting blood glucose (mg/dL) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in Fasting Insulin
Fasting insulin (µIU/mL) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in HbA1c
Glycated hemoglobin (HbA1c, %) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in LDL Cholesterol
LDL cholesterol (mg/dL) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in HDL Cholesterol
HDL cholesterol (mg/dL) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in Triglycerides
Triglycerides (mg/dL) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and postoperative 6 months
Change in Total Cholesterol
Total cholesterol (mg/dL) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and postoperative 6 months
Change in ALT
Alanine aminotransferase (ALT, U/L) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in AST
Aspartate aminotransferase (AST, U/L) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in Uric Acid
Uric acid (mg/dL) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in Urea
Urea (mg/dL) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in Hemoglobin
Hemoglobin (g/dL) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in Hematocrit
Hematocrit (%) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in Ferritin
Ferritin (ng/mL) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in Serum Iron
Serum iron (µg/dL) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in Vitamin B12
Vitamin B12 (pg/mL) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in Folic Acid
Folic acid (ng/mL) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in Magnesium
Magnesium (mg/dL) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in Total Calcium
Total calcium (mg/dL) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in Serum Sodium
Serum sodium (mEq/L) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Change in Serum Potassium
Serum potassium (mEq/L) obtained from routine clinical laboratory follow-up.
Measured: Preoperative and 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Sep 2026
- Study start1 Jul 2026
- Primary completion10 Jan 2027 (estimated)
- Study completion10 Feb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Obesity & OverweightStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 52 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Mudanya University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Seher Şen, Mudanya University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07809152
- Sponsor's protocol ID
- MUDU-SBE-SS-05
- Status last verified
- Sep 2026
- First submitted
- 29 Jul 2026
- Last updated
- 9 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared, as this was not planned or consented to as part of the study protocol. Data confidentiality was assured to participants at the time of enrollment, and no data sharing infrastructure or agreement is in place beyond the study team.
Study at a glance
From the registry record, last updated by the sponsor on 9 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Relationship Between Collagen-Containing Supplement Use and Muscle Mass and Body Image Following Metabolic and Bariatric Surgery: A Prospective Observational Study
- ClinicalTrials.gov ID
- NCT07809152
- Acronym / sponsor ID
- MUDU-SBE-SS-05
- Conditions
- Obesity & Overweight, Collagen Protein, Bariatric Surgery, Metabolic and Bariatric Surgery, Body Composition, Muscle Composition
- Keywords
- Bariatric Surgery, Collagen Supplementation, Muscle Mass, Body Composition
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 52 participants (estimated)
- Lead sponsor
- Mudanya UniversityUniversity, hospital or other
- Study start
- 1 Jul 2026 (actual)
- Primary completion
- 10 Jan 2027 (estimated)
- Study completion
- 10 Feb 2027 (estimated)
- First posted
- 9 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This prospective, observational cohort study aims to evaluate whether the use of collagen-containing supplements is associated with differences in muscle mass, body composition, and body image among patients who have undergone sleeve gastrectomy (SG). The study will be conducted at the General Surgery outpatient clinic of a private hospital in Bursa, Türkiye, between May 2026 and March 2027, and will enroll adult patients (aged 18-65 years) who meet current ASMBS/IFSO eligibility criteria for metabolic and bariatric surgery.
Participants will be naturally allocated into two observational groups based on their own choice to use or not use collagen-containing supplements; no supplement will be provided or recommended by the study team, and no intervention will be made to participants' standard clinical care. All patients will be followed according to routine clinical practice preoperatively and at 2 weeks, 1 month, 3 months, and 6 months postoperatively.
Primary outcome measures include anthropometric parameters (body weight, BMI, fat mass, fat mass percentage, fat-free mass, muscle mass, percentage of weight loss, percentage of excess weight loss, waist and hip circumference) assessed via bioelectrical impedance analysis (Tanita MC-780 MA), and body image assessed using the Turkish-validated Body Shape Questionnaire (BSQ). Secondary outcomes include biochemical parameters, comorbidities, and macronutrient intake data obtained from 3-day dietary records analyzed using the BEBİS nutrition software.
The study hypothesizes that patients using collagen-containing supplements will show significant differences in muscle mass and body composition parameters compared with non-users, and that supplement use will be significantly associated with BSQ scores. A sample size of approximately 52 participants per group was calculated using G*Power 3.1 (one-way ANOVA, Cohen's f = 0.25, α = 0.05, power = 0.80).
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 1. Grup | – | Dietary Supplement: Collagen-containing supplementGroup/Cohort Label: Collagen Supplement Users (Kolajen Kullananlar) Description: Participants who, based on their own preference, use a collagen-containing supplement product following sleeve gastrectomy, without any intervention or recommendation from the study team. |
| 2. Grup | – | –Group/Cohort Label: Non-Users of Collagen Supplement (Kolajen Kullanmayanlar) Description: Participants who do not use any collagen-containing supplement product following sleeve gastrectomy, followed under routine clinical care. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients aged 18-65 years who underwent sleeve gastrectomy and are under routine postoperative follow-up at the General Surgery outpatient clinic of a private hospital in Bursa, Türkiye. Eligible patients meet current ASMBS/IFSO criteria for metabolic and bariatric surgery (BMI ≥ 35 kg/m², or BMI 30-34.9 kg/m² with an obesity-related metabolic comorbidity). Participants are naturally grouped according to their own preference to use or not use a collagen-containing supplement following surgery.
Key inclusion criteria (5 listed)
- Patients with a BMI ≥ 35 kg/m², regardless of the presence of comorbidities
- Patients with a BMI of 30-34.9 kg/m² who have an obesity-related metabolic disease and are considered eligible for surgical treatment
- Patients who have undergone metabolic and bariatric surgery (MBS) in accordance with current ASMBS/IFSO guidelines (Eisenberg et al., 2022)
- Patients under regular postoperative follow-up
- Age 18-65 years
Key exclusion criteria (7 listed)
- Inflammatory bowel disease
- History of upper gastrointestinal bleeding
- Severe psychiatric disorders
- Active cancer diagnosis
- Pregnancy or breastfeeding
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Collagen-containing supplementCollagen-containing supplement products used at the participants' own discretion following sleeve gastrectomy. The type of product, daily dosage, and duration of use were self-reported by participants | Dietary supplement | 1. Grup |
Primary outcome
Change in Body Weight
Time frame: Preoperative, and postoperative 2 weeks, 1 month, 3 months, and 6 months
Body weight (kg) measured using a Tanita MC-780 MA device.
Change in Body Shape Questionnaire (BSQ) Score
Time frame: Preoperative and postoperative 6 months
Body image concerns were assessed using the Body Shape Questionnaire (BSQ-34), a validated instrument for the Turkish population. This 34-item self-report scale evaluates weight-related concerns and dissatisfaction with body shape over the preceding four weeks. Each item is scored from 1 (never) to 6 (always), with a total score range of 34 to 204. Higher scores indicate greater dissatisfaction with body shape, i.e., a worse outcome.
Change in Body Mass Index (BMI)
Time frame: Preoperative, and postoperative 2 weeks, 1 month, 3 months, and 6 months
BMI calculated as body weight (kg) divided by height squared (m²).
Percentage of Total Weight Loss (%TWL)
Time frame: Postoperative and 6 months
Calculated as (preoperative weight - postoperative weight) / preoperative weight × 100.
Percentage of Excess Weight Loss (%EWL)
Time frame: Postoperative and 6 months
Calculated as (preoperative weight - postoperative weight) / (preoperative weight - ideal weight) × 100. Ideal body weight was calculated assuming a BMI of 25 kg/m².
Change in Fat Mass
Time frame: Preoperative, and postoperative 2 weeks, 1 month, 3 months, and 6 months
Fat mass (kg) assessed by multi-frequency bioelectrical impedance analysis (BIA) using a Tanita MC-780 MA device.
Change in Fat Mass Percentage
Time frame: Preoperative, and postoperative 2 weeks, 1 month, 3 months, and 6 months
Fat mass expressed as a percentage of total body weight, assessed by bioelectrical impedance analysis (BIA) using a Tanita MC-780 MA device.
Change in Muscle Mass
Time frame: Preoperative, and postoperative 2 weeks, 1 month, 3 months, and 6 months
Muscle mass (kg) assessed by bioelectrical impedance analysis (BIA) using a Tanita MC-780 MA device.
Change in Muscle Mass Percentage
Time frame: Preoperative, and postoperative 2 weeks, 1 month, 3 months, and 6 months
Muscle mass expressed as a percentage of total body weight, assessed by bioelectrical impedance analysis (BIA) using a Tanita MC-780 MA device.
21 secondary outcomes
Change in Fasting Blood Glucose
Time frame: Preoperative and 6 months
Change in Fasting Insulin
Time frame: Preoperative and 6 months
Change in HbA1c
Time frame: Preoperative and 6 months
Change in LDL Cholesterol
Time frame: Preoperative and 6 months
Change in HDL Cholesterol
Time frame: Preoperative and 6 months
Change in Triglycerides
Time frame: Preoperative and postoperative 6 months
Change in Total Cholesterol
Time frame: Preoperative and postoperative 6 months
Change in ALT
Time frame: Preoperative and 6 months
Change in AST
Time frame: Preoperative and 6 months
Change in Uric Acid
Time frame: Preoperative and 6 months
Change in Urea
Time frame: Preoperative and 6 months
Change in Hemoglobin
Time frame: Preoperative and 6 months
Change in Hematocrit
Time frame: Preoperative and 6 months
Change in Ferritin
Time frame: Preoperative and 6 months
Change in Serum Iron
Time frame: Preoperative and 6 months
Change in Vitamin B12
Time frame: Preoperative and 6 months
Change in Folic Acid
Time frame: Preoperative and 6 months
Change in Magnesium
Time frame: Preoperative and 6 months
Change in Total Calcium
Time frame: Preoperative and 6 months
Change in Serum Sodium
Time frame: Preoperative and 6 months
Change in Serum Potassium
Time frame: Preoperative and 6 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Sep 2026.
- Individual participant dataSharing planned: No. Individual participant data will not be shared, as this was not planned or consented to as part of the study protocol. Data confidentiality was assured to participants at the time of enrollment, and no data sharing infrastructure or agreement is in place beyond the study team.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Emre Şen, Master's degree graduate contact
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Obesity & Overweight and Collagen Protein, run by Mudanya University at 1 site in Turkey (Türkiye).
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 5 inclusion and 7 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 9 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). 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 Seher Şen, Assistant Professor (+905393919700, seherdalli@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Body Weight (time frame: Preoperative, and postoperative 2 weeks, 1 month, 3 months, and 6 months). The study lists 9 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 9 Sep 2026.