Overweight and Obese AdultsGendAgeNCT07065643
Sex Hormones as Regulators of the Age- and Sex-dependent Benefits of Caloric Restriction
A study testing Phase 1 - Maintenance Diet and Phase 2 - Weight loss diet in people with Overweight and Obese Adults and Healthy, run by University of Aberdeen at 1 site in United Kingdom.
Trial summary
Obesity increases the risk of type 2 diabetes, cardiovascular disease, and certain cancers, primarily due to elevated abdominal fat storage. With nearly two-thirds of the UK population living with overweight or obesity, there is an urgent necessity for evidence-based public health guidance to promote healthy weight. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Overweight and Obese Adults, Healthy
- What is being tested?
- Phase 1 - Maintenance Diet and Phase 2 - Weight loss diet
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 75 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 9 Jul 2025to 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 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Adults (aged over 18years) who are healthy but overweight/obese (BMI 27-45kg/m2) males and females as:
- 15 women (age 40 or less years)
- 15 men (age 40 or less years)
- 15 women (age 55-65 years) in menopause*; not taking Hormone Replacement Therapy (HRT)
- 15 men (age 55-65 years)
- 15 women (age 55-65 years) in menopause; taking HRT**
- menopause definition is no menstrual period for 12 months **HRT inclusion criteria - women will have continuously taken oestrogen HRT for 24 months
Who cannot join
- Potential volunteers will be asked to fill in a health questionnaire at the screening visit to assess their suitability for the study. This information will allow us to exclude participants.
- Medication exclusion criteria, current use :-
- weight loss medication (e.g. GLP agonists), β-blockers, antihistamines, antipsychotics, benzodiazepines, barbiturates, melatonin, Ritalin, modafinil, soporifics, hypnotics, antiepileptic drugs, diabetes medication (e.g. metformin or insulin).
- Self-reported medical exclusion criteria:
- Females who are planning to be pregnant, are pregnant or are breastfeeding
- Anyone with coeliac disease or gluten intolerance or food allergy
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- Anyone with diagnosed T1 or T2 diabetes
- Anyone suffering from a psychiatric disorder or any type of substance abuse
- Other exclusion criteria
- Anyone following a vegetarian or vegan diet
- Anyone currently following a weight loss programme (that may be affecting lifestyle, physical activity \& diet) or undergone gastric band/reduction surgery; including GLP agonist (e.g. Semaglutide injection, Ozempic®).
- Anyone currently participating in another research study
- Anyone with unsuitable veins for blood sampling
- Anyone who is unable to fluently speak, read and understand English
- Anyone who is unable to comply to an alcohol-free diet for 6 weeks
- Anyone unable to give fully 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.
Marta Lonnie, Dr contact
United Kingdom1 site, 1 recruiting
- Recruiting
Rowett Institute, University of Aberdeen
Aberdeen
Alexandra M Johnstone, Professor, 01224 438614, alex.johnstone@abdn.ac.uk
Claire Fyfe, 01124 438753, c.fyfe@abdn.ac.uk
About this study
Official title: GendAge Weight Loss Study: Sex Hormones as Regulators of the Age- and Sex-dependent Benefits of Caloric Restriction
Obesity increases the risk of type 2 diabetes, cardiovascular disease, and certain cancers, primarily due to elevated abdominal fat storage. With nearly two-thirds of the UK population living with overweight or obesity, there is an urgent necessity for evidence-based public health guidance to promote healthy weight. Calorie deficit can facilitate weight loss and body fat reduction, leading to health benefits, such as improved blood glucose control. Current weight management advice centres on lifestyle modification, incorporating changes to diet and physical activity to support a calorie deficit. However, existing dieting recommendations fail to consider gender or age. This is a surprising oversight, as it is well established that health outcomes vary significantly between men and women across the lifespan. Further, the menopause may have an impact on fat storage linked to changes in sex hormones. Our recent research, involving both mice and humans, has indicated that females are less responsive to weight loss and fat reduction during dieting. This study aims to understand endocrine and metabolic sex-based differences in obesity and calorie restriction, with a particular focus on women's health. We plan to conduct a diet study with 75 participants, encompassing both younger and older men and women, to monitor changes in energy expenditure and body composition using gold-standard techniques, such as doubly-labelled water. Blood and abdominal fat tissue samples will be collected to investigate how sex hormones might elucidate these differences. The aim of the study is to enhance our understanding of diet and women's health to combat obesity and promote healthy ageing.
- Conditions
- Overweight and Obese Adults, Healthy
- Being tested
- Phase 1 - Maintenance Diet, Phase 2 - Weight loss diet
- Keywords
- caloric restriction, low calorie diet, menopause, overweight, obesity, weigh loss, ageing, energy expenditure, body composition
- Medical subject headings
- Overweight, Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Phase 1 - Maintenance DietOther
3d maintenance diet (MT, fixed macronutrient composition of 15% protein, 30% fat and 55% CHO), fed to energy requirements (1.3 X RMR)
Phase 2 - Weight loss dietOther
6 week calorie restricted high protein diet (CR, fixed macronutrient composition as 30% protein, 35% fat and 35% CHO) fed to energy requirements [0.8 X Resting Metabolic Rate (RMR)], with stepwise reduction of 100kcal/d at week 3 and 5
| Study group | Role | What they receive |
|---|---|---|
| Young women | Experimental | Age: 18 to 40 years old Receives: Other: Phase 1 - Maintenance Diet; Other: Phase 2 - Weight loss diet |
| Young men | Active comparator | Age: 18 to 40 years old Receives: Other: Phase 1 - Maintenance Diet; Other: Phase 2 - Weight loss diet |
| Older women (menopause & no-HRT) | Experimental | Age 55-65 years, in menopause, not taking Hormonal Replacement Therapy (HRT) Receives: Other: Phase 1 - Maintenance Diet; Other: Phase 2 - Weight loss diet |
| Older women (menopause & HRT) | Experimental | Age 55-65 years, in menopause, who have continuously taken oestrogen HRT for 24 months Receives: Other: Phase 1 - Maintenance Diet; Other: Phase 2 - Weight loss diet |
| Older men | Active comparator | Age 55-65 years Receives: Other: Phase 1 - Maintenance Diet; Other: Phase 2 - Weight loss diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in body mass expressed as weight in kilograms (kg)
Measured using digital scale
Measured: From baseline (day 1) to end of intervention (day 53); additional measurements taken three times a week throughout the intervention duration
Change in energy expenditure expressed in kilocalories per day (kcal/day)
Measured using stable isotope method - doubly labelled water (DLW) - with urine sample collection
Measured: From day 11 (start of the calorie-restricted diet) to the end of the intervention (day 52); with additional doses consumed on day 25 and 39
Secondary outcomes (12)
Change in resting metabolic rate (RMR) expressed in kcal/day
Measured using ventilated hood indirect calorimetry
Measured: From day 8 (start of the maintenance diet) to end of the intervention (day 53)
Change in bone mineral content in grams (g)
Measured using Dual Energy X-Ray Absorptiometry (DXA) scan
Measured: From day 8 (start of the maintenance diet) to end of the intervention (day 53)
Change in total body water (TBW) in litres (l)
Measured using deuterium dilution, with urine sample collection
Measured: From day 11 (start of the calorie-restricted diet) to end of the intervention (day 53)
Change in total body density expressed in litres (l)
Measured using BodPod air displacement plethysmography
Measured: From day 8 (start of the maintenance diet) to end of the intervention (day 53)
Change in body fat-mass percentage (%)
Derived from Lohman's 4-compartment model (body mass; body density; total body water; and bone mineral content)
Measured: From day 8 (start of the maintenance diet) to end of the intervention (day 53)
Change in non-esterified fatty acids (NEFA) concentration in fasted blood sample
Analysed by KONE
Measured: From day 8 (start of the maintenance diet) to end of the intervention (day 53); also measured at midpoint of calorie-restricted diet (day 32)
Change in concentration of caloric-restriction (CR) related hormones in fasted blood sample
Includes: leptin, adiponectin, cortisol; analysed by ELISA
Measured: From day 8 (start of the maintenance diet) to end of the intervention (day 53); also measured at midpoint of calorie restricted diet (day 32)
Change in sex hormones concentration in fasted blood sample
Includes: oestrogens, progesterone, androgens; analysed by high -sensitivity liquid chromatography-mass spectrometry (LC-MS)
Measured: From day 8 (start of the maintenance diet) to end of the intervention (day 53); also measured at midpoint of calorie restricted diet (day 32)
Body height measured in meters (m)
Measured using stadiometer
Measured: Only at baseline
Change in Body Mass Index (BMI) expressed as kg/m^2
BMI will be calculated using weight and height measures
Measured: From baseline (day 1) to end of intervention (day 53); additional measurements taken three times a week throughout the intervention duration
Change in adipose tissue metabolism assessed by adipocite size
Measured via abdominal subcutaneous fat biopsy using fine needle aspiration and histomorphometry method
Measured: From day 8 (start of the maintenance diet) to end of the intervention (day 53)
Change in adipose tissue metabolism assessed by phosphorylation of hormone-sensitive lipase (HSL)
Measured via abdominal subcutaneous fat biopsy using fine needle aspiration and immunoblotting method.
Measured: From day 8 (start of the maintenance diet) to end of the intervention (day 53)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Jul 2025
- Study start9 Jul 2025
- Primary completionDec 2027 (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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Factorial
- Masking
- None (open label)
- Enrolment
- 75 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Aberdeen
- Sponsor type
- University, hospital or other
- Collaborators
- University of Edinburgh
- Responsible party
- Sponsor
- Investigators
- Alexandra M Johnstone, Professor, Principal investigator, Rowett Institute, University of Aberdeen
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07065643
- Sponsor's protocol ID
- 822
- Other IDs
- 2-034-25
- Acronym
- GendAge
- Status last verified
- Jul 2025
- First submitted
- 3 Jul 2025
- Last updated
- 18 Jul 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: The study will be registered with ClinicalTrials.gov as a data repository. Links to IPD that underlie results in publications will be made available at the appropriate time through the project team's website which will contain a summary of the data compiled.
Study at a glance
From the registry record, last updated by the sponsor on 18 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- GendAge Weight Loss Study: Sex Hormones as Regulators of the Age- and Sex-dependent Benefits of Caloric Restriction
- ClinicalTrials.gov ID
- NCT07065643
- Acronym / sponsor ID
- GendAge / 822
- Conditions
- Overweight and Obese Adults, Healthy
- Keywords
- caloric restriction, low calorie diet, menopause, overweight, obesity, weigh loss, ageing, energy expenditure
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 75 participants (estimated)
- Lead sponsor
- University of AberdeenUniversity, hospital or other
- Collaborators
- University of Edinburgh
- Study start
- 9 Jul 2025 (actual)
- Primary completion
- Dec 2027 (estimated)
- Study completion
- Dec 2027 (estimated)
- First posted
- 15 Jul 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.
Obesity increases the risk of type 2 diabetes, cardiovascular disease, and certain cancers, primarily due to elevated abdominal fat storage. With nearly two-thirds of the UK population living with overweight or obesity, there is an urgent necessity for evidence-based public health guidance to promote healthy weight. Calorie deficit can facilitate weight loss and body fat reduction, leading to health benefits, such as improved blood glucose control. Current weight management advice centres on lifestyle modification, incorporating changes to diet and physical activity to support a calorie deficit. However, existing dieting recommendations fail to consider gender or age. This is a surprising oversight, as it is well established that health outcomes vary significantly between men and women across the lifespan. Further, the menopause may have an impact on fat storage linked to changes in sex hormones. Our recent research, involving both mice and humans, has indicated that females are less responsive to weight loss and fat reduction during dieting. This study aims to understand endocrine and metabolic sex-based differences in obesity and calorie restriction, with a particular focus on women's health. We plan to conduct a diet study with 75 participants, encompassing both younger and older men and women, to monitor changes in energy expenditure and body composition using gold-standard techniques, such as doubly-labelled water. Blood and abdominal fat tissue samples will be collected to investigate how sex hormones might elucidate these differences. The aim of the study is to enhance our understanding of diet and women's health to combat obesity and promote healthy ageing.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Factorial
- Masking
- None (open label)
- Number of arms
- 5
| Arm | Type | Receives |
|---|---|---|
| Young women | Experimental | Other: Phase 1 - Maintenance Diet, Other: Phase 2 - Weight loss dietAge: 18 to 40 years old |
| Young men | Active comparator | Other: Phase 1 - Maintenance Diet, Other: Phase 2 - Weight loss dietAge: 18 to 40 years old |
| Older women (menopause & no-HRT) | Experimental | Other: Phase 1 - Maintenance Diet, Other: Phase 2 - Weight loss dietAge 55-65 years, in menopause, not taking Hormonal Replacement Therapy (HRT) |
| Older women (menopause & HRT) | Experimental | Other: Phase 1 - Maintenance Diet, Other: Phase 2 - Weight loss dietAge 55-65 years, in menopause, who have continuously taken oestrogen HRT for 24 months |
| Older men | Active comparator | Other: Phase 1 - Maintenance Diet, Other: Phase 2 - Weight loss dietAge 55-65 years |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Adults (aged over 18years) who are healthy but overweight/obese (BMI 27-45kg/m2) males and females as:
- 15 women (age 40 or less years)
- 15 men (age 40 or less years)
- 15 women (age 55-65 years) in menopause*; not taking Hormone Replacement Therapy (HRT)
- 15 men (age 55-65 years)
Key exclusion criteria (16 listed)
- Potential volunteers will be asked to fill in a health questionnaire at the screening visit to assess their suitability for the study. This information will allow us to exclude participants.
- Medication exclusion criteria, current use :-
- weight loss medication (e.g. GLP agonists), β-blockers, antihistamines, antipsychotics, benzodiazepines, barbiturates, melatonin, Ritalin, modafinil, soporifics, hypnotics, antiepileptic drugs, diabetes medication (e.g. metformin or insulin).
- Females who are planning to be pregnant, are pregnant or are breastfeeding
- Anyone with coeliac disease or gluten intolerance or food allergy
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 |
|---|---|---|
| Phase 1 - Maintenance Diet3d maintenance diet (MT, fixed macronutrient composition of 15% protein, 30% fat and 55% CHO), fed to energy requirements (1.3 X RMR) | Other | Older men, Older women (menopause & HRT), Older women (menopause & no-HRT), Young men, Young women |
| Phase 2 - Weight loss diet6 week calorie restricted high protein diet (CR, fixed macronutrient composition as 30% protein, 35% fat and 35% CHO) fed to energy requirements [0.8 X Resting Metabolic Rate (RMR)], with stepwise reduction of 100kcal/d at week 3 and 5 | Other | Older men, Older women (menopause & HRT), Older women (menopause & no-HRT), Young men, Young women |
Primary outcome
Change in body mass expressed as weight in kilograms (kg)
Time frame: From baseline (day 1) to end of intervention (day 53); additional measurements taken three times a week throughout the intervention duration
Measured using digital scale
Change in energy expenditure expressed in kilocalories per day (kcal/day)
Time frame: From day 11 (start of the calorie-restricted diet) to the end of the intervention (day 52); with additional doses consumed on day 25 and 39
Measured using stable isotope method - doubly labelled water (DLW) - with urine sample collection
12 secondary outcomes
Change in resting metabolic rate (RMR) expressed in kcal/day
Time frame: From day 8 (start of the maintenance diet) to end of the intervention (day 53)
Change in bone mineral content in grams (g)
Time frame: From day 8 (start of the maintenance diet) to end of the intervention (day 53)
Change in total body water (TBW) in litres (l)
Time frame: From day 11 (start of the calorie-restricted diet) to end of the intervention (day 53)
Change in total body density expressed in litres (l)
Time frame: From day 8 (start of the maintenance diet) to end of the intervention (day 53)
Change in body fat-mass percentage (%)
Time frame: From day 8 (start of the maintenance diet) to end of the intervention (day 53)
Change in non-esterified fatty acids (NEFA) concentration in fasted blood sample
Time frame: From day 8 (start of the maintenance diet) to end of the intervention (day 53); also measured at midpoint of calorie-restricted diet (day 32)
Change in concentration of caloric-restriction (CR) related hormones in fasted blood sample
Time frame: From day 8 (start of the maintenance diet) to end of the intervention (day 53); also measured at midpoint of calorie restricted diet (day 32)
Change in sex hormones concentration in fasted blood sample
Time frame: From day 8 (start of the maintenance diet) to end of the intervention (day 53); also measured at midpoint of calorie restricted diet (day 32)
Body height measured in meters (m)
Time frame: Only at baseline
Change in Body Mass Index (BMI) expressed as kg/m^2
Time frame: From baseline (day 1) to end of intervention (day 53); additional measurements taken three times a week throughout the intervention duration
Change in adipose tissue metabolism assessed by adipocite size
Time frame: From day 8 (start of the maintenance diet) to end of the intervention (day 53)
Change in adipose tissue metabolism assessed by phosphorylation of hormone-sensitive lipase (HSL)
Time frame: From day 8 (start of the maintenance diet) to end of the intervention (day 53)
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 18 Jul 2025.
- Individual participant dataSharing planned: Yes. The study will be registered with ClinicalTrials.gov as a data repository. Links to IPD that underlie results in publications will be made available at the appropriate time through the project team's website which will contain a summary of the data compiled.
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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.
Marta Lonnie, Dr contact
Alexandra M Johnstone, Professor principal investigator
Rowett Institute, University of Aberdeen
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Phase 1 - Maintenance Diet and Phase 2 - Weight loss diet in people with Overweight and Obese Adults and Healthy, run by University of Aberdeen 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 7 inclusion and 16 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 18 Jul 2025. 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 Alexandra M. Johnstone, Professor (01224 438614, alex.johnstone@abdn.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in body mass expressed as weight in kilograms (kg) (time frame: From baseline (day 1) to end of intervention (day 53); additional measurements taken three times a week throughout the intervention duration). The study lists 2 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 18 Jul 2025.