Overweight and Obese AdultsNCT07774676
Effects of Obesity on Autophagy and mTORC1 Signalling in Skeletal Muscle
An observational study of Overweight and Obese Adults, run by University of Birmingham at 1 site in United Kingdom.
Trial summary
It is well known that individuals living with overweight or obesity are not able to activate skeletal muscle growth processes to the same extent as lean individuals following activities such as weightlifting (resistance exercise) or protein ingestion. Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Overweight and Obese Adults
- What is being tested?
- Skeletal muscle biopsy, venous blood sampling and Protein-Rich Beverage
- Type of treatment
- Surgery or procedure
- How many people
- 24 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 15 Apr 2026to Dec 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 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Participants will be recruited from around the West Midlands area via recruitment media.
Who may be able to join
- Age - 18-45yrs
- BMI - 18.5-24.9kg/m2 OR >28kg/m2 (self-declaration, or calculated by research team based on height and weight)
- Weight Stable i.e. no change in weight of more than 5% in previous 6 months
- Meeting UK Physical activity guidelines (150 mins moderate or 75 mins vigorous activity/wk)
- Not involved in structured exercise training in previous 6 months
- No other diagnosed metabolic or neuromuscular conditions (self-declaration)
Who cannot join
- Currently using anti-diabetes medication (insulin, metformin, sulphonylureas, meglitinides, thiazolidinediones, DPP- 4 inhibitors, GLP-1 inhibitors).
- Currently taking cholesterol lowering medications (statins)
- Currently engaged in active weight loss programmes or using weight loss medication
- Chronic kidney disease (moderate to severe reduction in kidney function), defined as eGFR <30 ml/min/1.73m2 identified by self declaration.
- Pregnant or breast feeding
- Currently using anti-coagulation medication
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- Hypothyroidism
- Type 1 diabetes
- Current or recent weakness/injury to either leg that may affect muscle function or ability to exercise
- Current gastrointestinal issue/condition that may affect digestion and absorption of protein drink
- Individuals who follow a vegan diet or have intolerance/allergies to Whey protein.
- Previous adverse reaction to local anaethetic (lidocaine or marcaine).
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site, 1 recruiting
- Recruiting
School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham
Birmingham, B152TT
Jennifer Barrett, PhD, +447875713844, j.s.barrett@bham.ac.uk
n.w.hodson@bham.ac.uk
About this study
Official title: Understanding the Effects of Obesity on Autophagic and mTORC1 Signalling Following Resistance Exercise and Protein Ingestion in Skeletal Muscle.
It is well known that individuals living with overweight or obesity are not able to activate skeletal muscle growth processes to the same extent as lean individuals following activities such as weightlifting (resistance exercise) or protein ingestion. However, the underlying cell signalling pathways which may be regulating these impairments are not fully understood. This study aims to understand if skeletal muscle signalling responses to resistance exercise and protein intake differ between lean individuals and those living with overweight or obesity. The investigators will recruit a cohort of lean individuals and a cohort of individuals living with overweight/obesity who will undertake a bout of single-leg resistance exercise and consume a protein-rich drink. Before and after this, muscle samples will be obtained from each leg of participants at different timepoints to understand the effects of exercise and feeding combined (exercised leg) and feeding alone (rested leg) on different cellular processes which regulate muscle growth. This will allow the investigators to understand if their are specific pathways within skeletal muscle which could be targeted in future interventions to overcome impaired protein metabolism in those living with overweight/obesity.
Read the detailed description
As skeletal muscle is a major contributor to basal metabolic rate and glucose control, increasing the quality of skeletal muscle in those living with obesity could improve the long-term success of subsequent weight loss programs. There are two main activities which are often recommended to improve skeletal muscle quality, resistance exercise (i.e. weightlifting) and adequate protein intake, however, recent research has suggested that individuals living with obesity do not respond as well to these activities as a non-obese person. This research project aims to investigate if certain processes within muscle cells, which regulate muscle size and quality, are reduced in people living with obesity following a single session of resistance exercise and a protein-rich drink. This will hopefully identify processes we can target specifically to improve skeletal muscle quality. The project involves participants attending the lab and completing a session of single-leg resistance exercise and ingesting a protein drink. Before and after this the investigators will take a number of blood samples and small pieces of muscle from each thigh to understand how muscle reacts to exercise/feeding and whether this differs between individuals with and without obesity. Following the visit investigators will the conduct a variety of laboratory analysis on these samples to understand the responses. Overall, this project has the potential to help design future programmes which can improve skeletal muscle quality in those living with obesity, improving general health and increasing success of weight loss interventions.
To date, the acute effects anabolic stimulation by resistance exercise and protein ingestion in individuals with obesity have been shown to be blunted. However, the mechanisms responsible for this have scarcely been investigated. We intend to build on current evidence by identifying what causes this blunted response to anabolic stimulation in individuals with obesity.
This project aims to determine whether individuals with obesity exhibit differential mTORC1-lysosomal translocation in response to anabolic signaling following a single bout of resistance exercise combined with protein ingestion.
- Conditions
- Overweight and Obese Adults
- Being tested
- Skeletal muscle biopsy, venous blood sampling, Protein-Rich Beverage, Single-leg resistance exercise, Dual-Energy X-ray Absorptiometry (DEXA) Scan
- Keywords
- Overweight, Obesity, Skeletal muscle, Autophagy, mTORC1 signalling, Protein metabolism
- Medical subject headings
- Overweight, Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Skeletal muscle biopsyProcedure or surgery
On five occasions throughout the experimental visit, skeletal muscle biopsies will be obtained from the vastus lateralis of participants (3 in rested leg, 2 in exercised leg). These will be completed under local anaesthetic using the Bergstrom needle technique, modified for suction.
venous blood samplingProcedure or surgery
Upon arrival at the experimental visit, participant will have a cannula inserted into their antecubital vein for repeated blood sampling. 12 blood samples will then be taken throughout the course of the experimental trial from which both plasma and serum will be isolated.
Protein-Rich BeverageDietary supplement
Following completion of the acute, single-leg resistance exercise bout, participants will consumed a protein-rich beverage containing 0.25g/kg bodyweight whey protein (dissolved in 300ml water).
Single-leg resistance exerciseOther
During the experimental visit, participants will complete an acute bout of single-leg knee extensions on a randomised leg. This will be comprised of 6 sets of knee extensions at 80% of participants pre-determined 1 repetition maximum (1RM), with each set completed to volitional failure separated by a 2 minute rest interval.
Dual-Energy X-ray Absorptiometry (DEXA) ScanRadiation
During Visit 1 of the study, participants will undergo a whole-body DEXA scan to assess body composition (body fat and fate-free mass). This short, painless scan exposes participants to a small amount of radiation which is equivalent to the amount exposed to during a transatlantic flight.
Maximal Strength TestingOther
Also called 1RM testing
During Visit 1 of the study, participants will undergo maximal knee extension strength testing using a randomised leg (which will complete exercise during experimental trial). This will involve increasing the weight on the knee extension machine until the participant can no longer complete a single repetition. This weight will then be used to calculate the workload at which the participant will complete the exercise bout during the experimental trial.
| Study group | Role | What they receive |
|---|---|---|
| Lean Individuals | This cohort will be aged between 18-45yrs and have a Body Mass index (BMI) of 18.5-25.9kg/m2. They will also have been weight-stable (<5% bodyweight change in previous 6 months). Receives: Procedure: Skeletal muscle biopsy; Procedure: venous blood sampling; Dietary Supplement: Protein-Rich Beverage; Other: Single-leg resistance exercise; Radiation: Dual-Energy X-ray Absorptiometry (DEXA) Scan; Other: Maximal Strength Testing | |
| Individuals with Overweight or Obesity | This cohort will be aged between 18-45yrs and have a Body Mass index (BMI) of >28kg/m2. They will also have been weight-stable (<5% bodyweight change in previous 6 months). Receives: Procedure: Skeletal muscle biopsy; Procedure: venous blood sampling; Dietary Supplement: Protein-Rich Beverage; Other: Single-leg resistance exercise; Radiation: Dual-Energy X-ray Absorptiometry (DEXA) Scan; Other: Maximal Strength Testing |
What is being measured
The primary outcome is the main question the study is designed to answer.
mTORC1-lysosomal translocation
The translocation of the mTORC1-lysosomal complex toward the cell periphery following resistance exercise and/or protein ingestion will be assessed in skeletal muscle cross sections via immunofluorescence microscopy.
Measured: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Secondary outcomes (3)
mTORC1 activation
Markers of mTORC1 activation (phosphorylation of downstream signalling targets) will be assessed via immunoblotting on homogenised skeletal muscle samples.
Measured: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Autophagic Flux
Skeletal muscle autophagic flux will be assessed on skeletal muscle samples using a novel ex vivo assay followed by immunoblotting.
Measured: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Lysosomal Content
Skeletal muscle lysosomal content will be assessed via immunoblotting for markers of the lysosome on homogenised skeletal muscle samples
Measured: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Aug 2026
- Study start15 Apr 2026
- Primary completionDec 2026 (estimated)
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Overweight and Obese AdultsStudies 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
- Cross-sectional
- Enrolment
- 24 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Birmingham
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Nathan Hodson, University of Birmingham
- Investigators
- Nathan Hodson, Principal investigator, University of Birmingham
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07774676
- Sponsor's protocol ID
- RG_25-084
- Status last verified
- Aug 2026
- First submitted
- 12 Aug 2026
- Last updated
- 19 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: IPD used in publications arising from the project will be shared upon request
Study at a glance
From the registry record, last updated by the sponsor on 19 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Understanding the Effects of Obesity on Autophagic and mTORC1 Signalling Following Resistance Exercise and Protein Ingestion in Skeletal Muscle.
- ClinicalTrials.gov ID
- NCT07774676
- Acronym / sponsor ID
- RG_25-084
- Conditions
- Overweight and Obese Adults
- Keywords
- Overweight, Obesity, Skeletal muscle, Autophagy, mTORC1 signalling, Protein metabolism
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 24 participants (estimated)
- Lead sponsor
- University of BirminghamUniversity, hospital or other
- Study start
- 15 Apr 2026 (actual)
- Primary completion
- Dec 2026 (estimated)
- Study completion
- Dec 2027 (estimated)
- First posted
- 19 Aug 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.
It is well known that individuals living with overweight or obesity are not able to activate skeletal muscle growth processes to the same extent as lean individuals following activities such as weightlifting (resistance exercise) or protein ingestion. However, the underlying cell signalling pathways which may be regulating these impairments are not fully understood. This study aims to understand if skeletal muscle signalling responses to resistance exercise and protein intake differ between lean individuals and those living with overweight or obesity. The investigators will recruit a cohort of lean individuals and a cohort of individuals living with overweight/obesity who will undertake a bout of single-leg resistance exercise and consume a protein-rich drink. Before and after this, muscle samples will be obtained from each leg of participants at different timepoints to understand the effects of exercise and feeding combined (exercised leg) and feeding alone (rested leg) on different cellular processes which regulate muscle growth. This will allow the investigators to understand if their are specific pathways within skeletal muscle which could be targeted in future interventions to overcome impaired protein metabolism in those living with overweight/obesity.
Detailed description
As skeletal muscle is a major contributor to basal metabolic rate and glucose control, increasing the quality of skeletal muscle in those living with obesity could improve the long-term success of subsequent weight loss programs. There are two main activities which are often recommended to improve skeletal muscle quality, resistance exercise (i.e. weightlifting) and adequate protein intake, however, recent research has suggested that individuals living with obesity do not respond as well to these activities as a non-obese person. This research project aims to investigate if certain processes within muscle cells, which regulate muscle size and quality, are reduced in people living with obesity following a single session of resistance exercise and a protein-rich drink. This will hopefully identify processes we can target specifically to improve skeletal muscle quality. The project involves participants attending the lab and completing a session of single-leg resistance exercise and ingesting a protein drink. Before and after this the investigators will take a number of blood samples and small pieces of muscle from each thigh to understand how muscle reacts to exercise/feeding and whether this differs between individuals with and without obesity. Following the visit investigators will the conduct a variety of laboratory analysis on these samples to understand the responses. Overall, this project has the potential to help design future programmes which can improve skeletal muscle quality in those living with obesity, improving general health and increasing success of weight loss interventions.
To date, the acute effects anabolic stimulation by resistance exercise and protein ingestion in individuals with obesity have been shown to be blunted. However, the mechanisms responsible for this have scarcely been investigated. We intend to build on current evidence by identifying what causes this blunted response to anabolic stimulation in individuals with obesity.
This project aims to determine whether individuals with obesity exhibit differential mTORC1-lysosomal translocation in response to anabolic signaling following a single bout of resistance exercise combined with protein ingestion.
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Lean Individuals | – | Procedure: Skeletal muscle biopsy, Procedure: venous blood sampling, Dietary Supplement: Protein-Rich Beverage, Other: Single-leg resistance exercise, Radiation: Dual-Energy X-ray Absorptiometry (DEXA) Scan, Other: Maximal Strength TestingThis cohort will be aged between 18-45yrs and have a Body Mass index (BMI) of 18.5-25.9kg/m2. They will also have been weight-stable (<5% bodyweight change in previous 6 months). |
| Individuals with Overweight or Obesity | – | Procedure: Skeletal muscle biopsy, Procedure: venous blood sampling, Dietary Supplement: Protein-Rich Beverage, Other: Single-leg resistance exercise, Radiation: Dual-Energy X-ray Absorptiometry (DEXA) Scan, Other: Maximal Strength TestingThis cohort will be aged between 18-45yrs and have a Body Mass index (BMI) of >28kg/m2. They will also have been weight-stable (<5% bodyweight change in previous 6 months). |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Participants will be recruited from around the West Midlands area via recruitment media.
Key inclusion criteria (6 listed)
- Age - 18-45yrs
- BMI - 18.5-24.9kg/m2 OR >28kg/m2 (self-declaration, or calculated by research team based on height and weight)
- Weight Stable i.e. no change in weight of more than 5% in previous 6 months
- Meeting UK Physical activity guidelines (150 mins moderate or 75 mins vigorous activity/wk)
- Not involved in structured exercise training in previous 6 months
Key exclusion criteria (12 listed)
- Currently using anti-diabetes medication (insulin, metformin, sulphonylureas, meglitinides, thiazolidinediones, DPP- 4 inhibitors, GLP-1 inhibitors).
- Currently taking cholesterol lowering medications (statins)
- Currently engaged in active weight loss programmes or using weight loss medication
- Chronic kidney disease (moderate to severe reduction in kidney function), defined as eGFR <30 ml/min/1.73m2 identified by self declaration.
- Pregnant or breast feeding
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 |
|---|---|---|
| Skeletal muscle biopsyOn five occasions throughout the experimental visit, skeletal muscle biopsies will be obtained from the vastus lateralis of participants (3 in rested leg, 2 in exercised leg). These will be completed under local anaesthetic using the Bergstrom needle technique, modified for suction. | Procedure or surgery | Individuals with Overweight or Obesity, Lean Individuals |
| venous blood samplingUpon arrival at the experimental visit, participant will have a cannula inserted into their antecubital vein for repeated blood sampling. 12 blood samples will then be taken throughout the course of the experimental trial from which both plasma and serum will be isolated. | Procedure or surgery | Individuals with Overweight or Obesity, Lean Individuals |
| Protein-Rich BeverageFollowing completion of the acute, single-leg resistance exercise bout, participants will consumed a protein-rich beverage containing 0.25g/kg bodyweight whey protein (dissolved in 300ml water). | Dietary supplement | Individuals with Overweight or Obesity, Lean Individuals |
| Single-leg resistance exerciseDuring the experimental visit, participants will complete an acute bout of single-leg knee extensions on a randomised leg. This will be comprised of 6 sets of knee extensions at 80% of participants pre-determined 1 repetition maximum (1RM), with each set completed to volitional failure separated by a 2 minute rest interval. | Other | Individuals with Overweight or Obesity, Lean Individuals |
| Dual-Energy X-ray Absorptiometry (DEXA) ScanDuring Visit 1 of the study, participants will undergo a whole-body DEXA scan to assess body composition (body fat and fate-free mass). This short, painless scan exposes participants to a small amount of radiation which is equivalent to the amount exposed to during a transatlantic flight. | Radiation | Individuals with Overweight or Obesity, Lean Individuals |
| Maximal Strength TestingAlso: 1RM testingDuring Visit 1 of the study, participants will undergo maximal knee extension strength testing using a randomised leg (which will complete exercise during experimental trial). This will involve increasing the weight on the knee extension machine until the participant can no longer complete a single repetition. This weight will then be used to calculate the workload at which the participant will complete the exercise bout during the experimental trial. | Other | Individuals with Overweight or Obesity, Lean Individuals |
Primary outcome
mTORC1-lysosomal translocation
Time frame: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
The translocation of the mTORC1-lysosomal complex toward the cell periphery following resistance exercise and/or protein ingestion will be assessed in skeletal muscle cross sections via immunofluorescence microscopy.
3 secondary outcomes
mTORC1 activation
Time frame: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Autophagic Flux
Time frame: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Lysosomal Content
Time frame: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
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 19 Aug 2026.
- Individual participant dataSharing planned: Yes. IPD used in publications arising from the project will be shared upon request
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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.
Nathan Hodson principal investigator
University of Birmingham
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 Overweight and Obese Adults, run by University of Birmingham at 1 site in United Kingdom.
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 12 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 19 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 1 site in United Kingdom. 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 Jennifer Barrett, PhD (+447875713844, j.s.barrett@bham.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
mTORC1-lysosomal translocation (time frame: From completion of experimental testing/biosample collection until end of study, an average of 1 year.). 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 19 Aug 2026.