How sex hormones affect the age- and sex-related benefits of a low-calorie diet
GendAge Weight Loss Study: Sex Hormones as Regulators of the Age- and Sex-dependent Benefits of Caloric Restriction
This trial tests whether sex hormones explain why adults of different ages and sexes lose fat and get different health benefits when they follow a low-calorie diet.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 75 (estimated) |
| Ages | 18 Years to 65 Years |
| Sex | All |
| Sponsor | University of Aberdeen Academic / other |
| Locations | 1 site (Aberdeen) |
| Trial ID | NCT07065643 on ClinicalTrials.gov |
What this trial studies
The study enrolls healthy adults with BMI 27–45 kg/m2 and places them on a controlled diet program with an initial maintenance phase followed by a supervised weight-loss (calorie-restricted) phase. Participants are grouped by sex and age (younger ≤40 and older 55–65) with older women split by menopausal status and HRT use, allowing comparison across five cohorts. Researchers will measure body composition, blood glucose and metabolic markers, and sex hormone levels to link hormonal status with changes in fat loss and metabolic outcomes. People on excluded medications or with disqualifying health conditions are screened out to reduce confounding effects.
Who should consider this trial
Good fit: Healthy adults aged over 18 with BMI 27–45 kg/m2, including men and women divided into younger (≤40) and older (55–65) groups, with older women both on and off oestrogen HRT.
Not a fit: People outside the specified age or BMI ranges, those taking excluded medications (for example weight-loss drugs, certain psychotropics, or diabetes medications), or those with significant medical issues are unlikely to gain benefit from participation.
Why it matters
Potential benefit: If successful, the results could help tailor weight-loss advice by age, sex, and menopausal/HRT status to improve fat loss and metabolic health for different groups.
How similar studies have performed: Prior animal studies and some human work suggest sex differences in response to calorie restriction, but directly testing the role of sex hormones and HRT in middle-aged adults is relatively novel.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion criteria * 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 Exclusion criteria: 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 * 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
Where this trial is running
Aberdeen
- Rowett Institute, University of Aberdeen — Aberdeen, United Kingdom (Recruiting)
Study contacts
- Principal investigator: Alexandra M Johnstone, Professor — Rowett Institute, University of Aberdeen
- Study coordinator: Alexandra M. Johnstone, Professor
- Email: alex.johnstone@abdn.ac.uk
- Phone: 01224 438614
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.