Skip to main content

Take part in our study about body size and metabolic health

We are inviting you take part in our study investigating the metabolism of individuals with extreme body size to manage health risks.

Research background

Health advice should be appropriate for people of all body sizes.

By better understanding how body size and scale could change how the body processes food, or how being bigger or smaller may influence eating habits, we will be able to better inform healthy living guidelines to tackle issues such as obesity and being overweight in these populations.

With help from our Department of Psychology, we will also be able to investigate whether the mental health of these individuals has been affected by their size.

A final component of our analysis will be the efficiency of movement for these individuals, with the help of our biomechanics department. On the whole, this study will involve one 24-hour visit to a research laboratory at the University of Bath, followed by free-living monitoring of normal physical activity and eating routines for two weeks.

Study dates

  • Start date: 1 April 2023
  • End date: 28 September 2025

Participant eligibility

You can participate if you are aged 16 years or over, and you meet the criteria of extreme body size:

  • Males with extreme large body size (>75 kg fat-free mass)
  • Females with extreme large body size (>57.25 kg fat-free mass)
  • Males with extreme small body size (<47.4 kg fat-free mass)
  • Females with extreme small body size (<35 kg fat-free mass)

Individuals with hormonal or genetic conditions affecting growth, such as skeletal dysplasia, may also be eligible (see exclusion criteria below).

Exclusion criteria

You are not eligible if:

  • you have a diagnosed history of eating disorders (e.g., anorexia)
  • you have known bleeding disorders (exclusion for biopsies only)
  • you have a known allergy or intolerance to lidocaine (anaesthetic)
  • have not been weight stable (i.e., >3 kg change in body mass in past 3 months)
  • are pregnant or lactating

Your data

Throughout the study, all documents will only contain your unique study code which you will be assigned if you enrol.

Any identifiable personal data will be kept on a password-protected file on the University’s servers, in accordance with the current UK Data Protection regulations.

Relevant ethics approval information

The study has been approved by the South West - Central Bristol Research Ethics Committee and has been noted by the Biomedical Sciences Research Ethics Committee at the University of Bath. 1

What you'll do

During a 24-hour visit to the research laboratory, we will take basic measurements of the body, including how much muscle and fat you have. We'll then provide you with a variety of foods to eat to see how your body responds, for example we'll look at changes in your blood sugar levels.

You will also complete some questionnaires regarding your eating habits and state of mental health, as well as completing a brief exercise test.

Finally, we will ask you to record your physical activity and what you eat for 14 days after the laboratory visit to monitor your natural behaviour.

Testing will be completed at the University of Bath within a research team highly experienced in human research.

Stethoscope with heart beat report and doctor analyzing checkup on laptop in health medical laboratory background

What you'll get for taking part

By taking part in this study, you will be making a valuable contribution to scientific knowledge and will help to pioneer this area of research. You will also receive:

  • a detailed analysis of your diet, including calorie intake and macronutrient composition
  • a detailed breakdown of how much energy you burn at rest and during physical activity
  • feedback on your body measurements, such as body fat percentage and waist:hip ratio
  • feedback on metabolites and hormones in your blood in response to feeding
Girl holding a notebook

Contact the lead researcher, Lucy Merrell, to sign-up or ask questions

Email Lucy Merrell

1 The study has been approved by the South West - Central Bristol Research Ethics Committee (ref 23/SW/0035) and has been noted by the Biomedical Sciences Research Ethics Committee at the University of Bath.

  1.  ↩