Dietitians promote good dietary health and treat nutritional problems by providing practical advice about food choices, based on scientific research. The ability to interact well with people from a wide range of backgrounds is essential. Dietitians work on a group and an individual basis with people of all ages. A dietitian is an expert in dietetics; that is, human nutrition and the regulation of diet. A dietitian alters their patient’s nutrition based upon their medical condition and individual needs. Dietitians are regulated healthcare professionals licensed to assess, diagnose, and treat nutritional problems.