A dietitian is a professional who applies the science of food and nutrition to promote health, prevent and treat disease to optimise the health of individuals, groups, communities and populations. The profession of dietetics contributes to the promotion of health and the prevention and treatment of illness by optimising the nutrition of populations, communities and individuals. Dietitians have a defined and recognisable body of knowledge and utilise scientific principles and methods in the study of nutrition and dietetics, applying these results to influence the wider environment affecting food intake and eating behaviour. The scope of dietetic practice is such that dietitians may work in a variety of settings and have a variety of work functions.