Study visits
For any queries, please email nutritionvolunteers@reading.ac.uk.
You may be required to come to the unit for periodic study visits. The time commitment required varies from study to study.
The techniques that take place during the visits also differ depending on the specific study requirements. See current studies for details.
Study techniques
Bioelectrical impedance
During the bioelectrical impedance or Tanita measurement, you will be asked to stand barefoot on the specialised weighing scales and grip a portable handle in each hand. During the 30-second measurement period, a small electrical current, that you will feel no sensation from, is sent around the body's tissues. This measurement can be used to predict the percentage of body fat in an individual.
Blood sampling (cannulation)
Some studies require volunteers to provide numerous blood samples over a study day period. For these studies, a nurse will insert a small flexible cannula into a vein in the volunteer's arm. This cannula will remain in place with minimal discomfort throughout the visit.
DXA scan
Measurement of body composition and bone mineral density can be assessed by dual-energy x-ray absorptiometry (DXA). During the DXA scan, the volunteer is required to lie on their back on the scanner bed while the scanner arm moves over their body. A scan of the whole body takes less than 15 minutes to complete. A DXA scan works in a similar manner to an X-ray but the radiation dose is considerably less.
Flow-mediated dilatation
Flow-mediated dilatation (FMD) is a safe and non-invasive technique that examines the health of the blood vessel in the arm using ultrasound. A cuff similar to that used to measure blood pressure is positioned just under the crease of the elbow. This cuff is inflated until its pressure or tightness prevents the blood from entering your forearm. It is held at this pressure for 5 minutes, and then the pressure will be released. Ultrasound is used to visualise the major blood vessel in the upper arm from which the blood vessel diameter can be measured. The pressure of the cuff may feel a little uncomfortable, particularly towards the end of the 5-minute period but the discomfort is almost immediately relieved once the cuff is deflated.
