I am a clinical researcher working in the field of obesity research. My research program examines the mechanisms of nervous system dysfunction in obese people and the benefits of lifestyle changes — such as weight loss and exercise — and drug treatments.Clinical trials address specific questions relevant to our understanding of disease processes or to the benefits of specific treatments. Ultimately, health care practice is based on knowledge derived from clinical trials. Our weight loss research has resulted in new knowledge regarding the benefits of weight loss on nervous system function, and also in identifying factors that influence successful weight loss.For participants involved in trials, there can be health benefits. For example, many of our patients experience improvements in cholesterol profile, blood pressure, fasting sugar and sugar tolerance. One of my weight loss volunteers lost 18 kilograms five years ago and still emails me every year to report on his weight!Potential participants undergo detailed screening investigations including blood tests, electrocardiogram and physical examination so they gain information about their current health status. We also perform many specialised tests that are not conducted outside the research setting, for example measurement of sugar handling using the ‘clamp method’.In one participant, who underwent an ultrasound of the heart as part of the study protocol, we discovered evidence of a previous silent heart attack that he was unaware of. Thus we were able to institute appropriate treatments to reduce risk of further heart damage.I think participation in a clinical trial can enhance a participant’s health awareness, for example they might gain an understanding of healthy eating patterns and caloric restriction. They also learn about the scientific effort in our hospitals and research institutes. I believe it is a positive experience.I would encourage participation in clinical trials. Individuals may derive both a personal benefit and they make a huge contribution to society as a whole. We are most appreciative of their time and effort in furthering scientific knowledge.