Nutritional science deals with the effect of the food we consume on our bodies, while dietetics applies the science of nutrition to the prevention and treatment of disease and the promotion of health.Dietitians assess, diagnose and treat diet and nutrition problems at an individual and wider public health level. They use up-to-date public health and scientific research on food, society, health and disease, which they translate into practical guidance to enable people to make appropriate lifestyle and food choices.