Dietetics is the application of the science of food and nutrition to help prevent and treat disease, and to maintain and promote health. Dieticians are practitioners of dietetics, who have undertaken training in hospital and community settings, and specially trained to give practical advice about diets using evidence-based approaches. Dietetics involves designing individual nutritional therapies to address specific health issues, such as unhealthy weight, diabetes or hypertension; developing facility-wide nutrition programs for health care, educational, correctional and other institutions; increasing public awareness of proper nutritional standards and habits; improving the accuracy and comprehension of food labels; ensuring the safety of the food supply; researching how changes in diet (such as reducing salt intake) affect health (by reducing blood pressure); working with food manufacturers to improve the nutritional quality of prepared foods. Further, dietetics also help to address issues such as weight again after an illness, HIV, eating disorders, sports performance and allergies.