Sex Hormones as Regulators of the Age- and Sex-dependent Benefits of Caloric Restriction

Launched by UNIVERSITY OF ABERDEEN · Jul 3, 2025

Keywords

ClinConnect Summary

This clinical trial is looking at how sex hormones (like estrogen and testosterone) affect weight loss and body fat changes in overweight and obese adults when they reduce their calorie intake. Researchers want to understand why men and women, especially women before and after menopause, may respond differently to dieting. This is important because many current weight loss guidelines don’t consider differences between ages and genders, even though these factors can impact how the body stores fat and uses energy. By studying these differences, the research aims to improve advice on healthy eating and weight management, particularly to support women’s health and healthy aging.

The study will include 75 adults who are overweight or obese, split into groups of younger and older men and women, including women who are menopausal—with some taking hormone replacement therapy and others not. Participants will follow a diet with fewer calories for several weeks while the researchers measure changes in body fat, energy use, and hormone levels through blood tests and fat tissue samples. To join, volunteers need to be healthy adults over 18 with a body mass index (BMI) between 27 and 45, not currently on certain medications or weight loss programs, and able to avoid alcohol for six weeks. The study is not yet recruiting but hopes to provide new insights into how diet and hormones interact to support better weight management for everyone.

Gender

ALL

Eligibility 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