Bariatric Surgery PatientsNCT07178704
The Metabolic and Genetic Drivers of Body Composition Changes Following Weight Loss Surgery
An observational study of Bariatric Surgery Patients, run by The University of Texas Medical Branch, Galveston at 1 site in United States.
Trial summary
Weight loss surgery is very good at reducing body weight but it can also cause the loss of both muscle and strength. Some patients undergoing weight loss surgery do not achieve their weight loss goals and regain the weight they lost. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Bariatric Surgery Patients
- How many people
- 100 participants
- Where
- 1 siteUnited States
- Study dates
- 4 Nov 2025to Aug 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: Patients will be recruited from those electing to undergo bariatric surgery at the University of Texas Medical Branch.
Who may be able to join
- Age: 18 to 65 years at time of consent
- BMI: 35-65 kg.m-2
- Scheduled to undergo bariatric surgery at UTMB
- All races and ethnic backgrounds
- Ability to speak and read English
- Subject has provided informed consent in a manner approved by the IRB and is willing and able to comply with the trial procedures.
Who cannot join
- Fails the medical criteria for bariatric surgery.
- Anemia (hematocrit < 33 % or donated blood in the past 12 weeks.)
- Recent (5 years or less) history of cancer
- Systemic steroids or immunosuppressant use for 8 or more consecutive days in the past 6 months, or any use of anabolic steroids or growth hormones in the same period.
- Body mass index < 35 or > 65 kg.m-2.
- Acute infectious disease or chronic infection.
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- Pregnancy or breast-feeding.
- Any medical condition that, in the opinion of the investigator, would place the subject at increased risk for participation.
- History of prior non-compliance that would, in the opinion of the investigator, make it difficult for the subject to comply with the study procedures or follow the investigator's instructions.
- Concurrent participation in another research study.
- Use of an investigational agent in the 30 days prior to signing informed consent.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
The University of Texas Medical Branch
Galveston, Texas, 77555
Emily J Lantz, PhD, 409-772-0643, ejlantz@utmb.edu
Emily J Lantz, PhD
About this study
Official title: PILOT STUDY: The Metabolic and Genetic Drivers of Body Composition Changes Following Weight Loss Surgery
Weight loss surgery is very good at reducing body weight but it can also cause the loss of both muscle and strength. Some patients undergoing weight loss surgery do not achieve their weight loss goals and regain the weight they lost. When this occurs, the loss of muscle and strength combined with the regain of weight can impact the individual's quality of life and ability to remain active and mobile.
The purpose of this study is to understand the behavioral, biological, and genetic factors that influence the success of weight loss surgery and its impact on muscle mass.
Bariatric surgery patients participating in the trial will be monitored prior to, and for a year following weight loss surgery, with data collected about their eating habits, hand grip strength, and the loss of fat, muscle, and body weight following surgery. In patients who undergo a routine endoscopy in advance of weight loss surgery a small sample of gut tissue will be collected to identify the expression (activity) of genes in their DNA.
- Conditions
- Bariatric Surgery Patients
- Keywords
- Body composition, Sarcopenia, Weight loss surgery, Muscle function, Protein metabolism
- Medical subject headings
- Sarcopenia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Bariatric Surgery Patients | Patients due to undergo either sleeve gastrectomy or gastric bypass surgery. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Body composition
Body composition will be determined in patients by whole-body bioelectrical impedance. Regional body composition will be additionally assessed in healthy volunteers and bariatric surgery patients undergoing metabolic assessment via whole-body dual-energy x-ray absorptiometry (DXA) imaging. Procedures will be performed on a single occasion in healthy volunteers and up to three times in bariatric patients undergoing metabolic assessment.
Measured: Measured at baseline in both healthy volunteers & bariatric surgery patients undergoing metabolic assessment. The latter will undergo repeat assessment on two further occasions across a 1 year period post surgery.
Secondary outcomes (5)
Dietary Protein Intake
Dietary protein intake will be determined by participants completing three-day food diaries. This will be performed on a single occasion in healthy volunteers and up to three occasions in bariatric patients undergoing metabolic assessment.
Measured: Measured at baseline in both healthy volunteers & patients undergoing metabolic assessment. The latter will undergo repeat assessment on two further occasions across a 1 year period post surgery.
Body weight
Body weight will be determined using digital scales (in kg). Procedures will be performed on a single occasion in healthy volunteers and up to three times in bariatric patients.
Measured: Measured at baseline in both healthy volunteers & bariatric surgery patients. The latter will undergo repeat assessment on two further occasions across a 1 year period post surgery.
Association between foregut gene expression and degree of weight reduction
Assessed only in patients. Gene expression of the foregut will be analyzed in tissue collected from patients during the routine pre-operative upper endoscopy. Subsequently, participants will be stratified into those achieving: <10%, 10-20%, or >20% weight loss 12 months post-surgery, and differentially expressed genes between the three groups determined.
Measured: A single occasion from tissue collected during the routine pre-operative upper endoscopy. (baseline)
Handgrip Strength
Assessed using a handgrip dynamometer (in kg). Will be performed on a single occasion in healthy volunteers and up to three times in bariatric patients.
Measured: Measured at baseline in both healthy volunteers & bariatric surgery patients. The latter will undergo repeat assessment on two further occasions across a 1 year period post surgery.
Energy Intake
Energy intake assessed via the completion of a 3-day food diary. Will be performed on a single occasion in healthy volunteers and up to three times in bariatric patients undergoing metabolic assessment.
Measured: Measured at baseline in both healthy volunteers & bariatric surgery patients undergoing metabolic assessment. The latter will undergo repeat assessment on two further occasions across a 1 year period post surgery.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Sep 2025
- Study start4 Nov 2025
- Primary completionFeb 2027 (estimated)
- Study completionAug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Bariatric Surgery PatientsStudies of the same condition, open and under way.
- More trials run by The University of Texas Medical Branch, GalvestonThe sponsor's other registered studies.
- 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
- 100 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Emily J Lantz, PhD, Principal investigator, The University of Texas Medical Branch
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07178704
- Sponsor's protocol ID
- 24-0361
- Status last verified
- Jul 2026
- First submitted
- 22 Aug 2025
- Last updated
- 10 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Given the small participant numbers involved, the sharing of individual participant data could carry the risk of re-identification of the study participants, despite the data being provided in de-identified form.
Study at a glance
From the registry record, last updated by the sponsor on 10 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- PILOT STUDY: The Metabolic and Genetic Drivers of Body Composition Changes Following Weight Loss Surgery
- ClinicalTrials.gov ID
- NCT07178704
- Acronym / sponsor ID
- 24-0361
- Conditions
- Bariatric Surgery Patients
- Keywords
- Body composition, Sarcopenia, Weight loss surgery, Muscle function, Protein metabolism
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- The University of Texas Medical Branch, GalvestonUniversity, hospital or other
- Study start
- 4 Nov 2025 (actual)
- Primary completion
- Feb 2027 (estimated)
- Study completion
- Aug 2027 (estimated)
- First posted
- 17 Sep 2025 (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.
Weight loss surgery is very good at reducing body weight but it can also cause the loss of both muscle and strength. Some patients undergoing weight loss surgery do not achieve their weight loss goals and regain the weight they lost. When this occurs, the loss of muscle and strength combined with the regain of weight can impact the individual's quality of life and ability to remain active and mobile.
The purpose of this study is to understand the behavioral, biological, and genetic factors that influence the success of weight loss surgery and its impact on muscle mass.
Bariatric surgery patients participating in the trial will be monitored prior to, and for a year following weight loss surgery, with data collected about their eating habits, hand grip strength, and the loss of fat, muscle, and body weight following surgery. In patients who undergo a routine endoscopy in advance of weight loss surgery a small sample of gut tissue will be collected to identify the expression (activity) of genes in their DNA.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Bariatric Surgery Patients | – | –Patients due to undergo either sleeve gastrectomy or gastric bypass surgery. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Patients will be recruited from those electing to undergo bariatric surgery at the University of Texas Medical Branch.
Key inclusion criteria (6 listed)
- Age: 18 to 65 years at time of consent
- BMI: 35-65 kg.m-2
- Scheduled to undergo bariatric surgery at UTMB
- All races and ethnic backgrounds
- Ability to speak and read English
Key exclusion criteria (11 listed)
- Fails the medical criteria for bariatric surgery.
- Anemia (hematocrit < 33 % or donated blood in the past 12 weeks.)
- Recent (5 years or less) history of cancer
- Systemic steroids or immunosuppressant use for 8 or more consecutive days in the past 6 months, or any use of anabolic steroids or growth hormones in the same period.
- Body mass index < 35 or > 65 kg.m-2.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Body composition
Time frame: Measured at baseline in both healthy volunteers & bariatric surgery patients undergoing metabolic assessment. The latter will undergo repeat assessment on two further occasions across a 1 year period post surgery.
Body composition will be determined in patients by whole-body bioelectrical impedance. Regional body composition will be additionally assessed in healthy volunteers and bariatric surgery patients undergoing metabolic assessment via whole-body dual-energy x-ray absorptiometry (DXA) imaging. Procedures will be performed on a single occasion in healthy volunteers and up to three times in bariatric patients undergoing metabolic assessment.
5 secondary outcomes
Dietary Protein Intake
Time frame: Measured at baseline in both healthy volunteers & patients undergoing metabolic assessment. The latter will undergo repeat assessment on two further occasions across a 1 year period post surgery.
Body weight
Time frame: Measured at baseline in both healthy volunteers & bariatric surgery patients. The latter will undergo repeat assessment on two further occasions across a 1 year period post surgery.
Association between foregut gene expression and degree of weight reduction
Time frame: A single occasion from tissue collected during the routine pre-operative upper endoscopy. (baseline)
Handgrip Strength
Time frame: Measured at baseline in both healthy volunteers & bariatric surgery patients. The latter will undergo repeat assessment on two further occasions across a 1 year period post surgery.
Energy Intake
Time frame: Measured at baseline in both healthy volunteers & bariatric surgery patients undergoing metabolic assessment. The latter will undergo repeat assessment on two further occasions across a 1 year period post surgery.
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 10 Jul 2026.
- Individual participant dataSharing planned: No. Given the small participant numbers involved, the sharing of individual participant data could carry the risk of re-identification of the study participants, despite the data being provided in de-identified form.
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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.
Emily J Lantz, PhD principal investigator
The University of Texas Medical Branch
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 Bariatric Surgery Patients, run by The University of Texas Medical Branch, Galveston at 1 site in United States.
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 6 inclusion and 11 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 10 Jul 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 United States. 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 Emily J Lantz, PhD (409-772-0643, ejlantz@utmb.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Body composition (time frame: Measured at baseline in both healthy volunteers & bariatric surgery patients undergoing metabolic assessment. The latter will undergo repeat assessment on two further occasions across a 1 year period post surgery.). 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 10 Jul 2026.