The title dietitian is protected by the Health Professional Council so that only qualified practitioners who have met the education requirements can use the title dietitian.

All registered dietitians (RDs) have a university degree or post-graduate qualification which involves nutrition science theory and supervised training in both clinical and community settings. Many dietitians work in hospitals and the community, advising individuals in need of therapeutic diets, but dietitians also work in many other areas supporting public health through improved food choices.

Dietitians are expert in both the science and the communication of nutrition, and registration ensures that dietitians practice to a code of ethics, and maintain professional development. Most dietitians are also members of their professional body, the British Dietetic Association.

The title nutritionist is less defined, and is not protected. There are several degree level courses in nutrition, and upon qualification, many register as nutritionists (RNutr) or as public health nutritionists (RPHNutr) with The Nutrition Society. Nutritionists work in government, industry, sports, education, media and for charities, supporting the collection and communication of information about food and health. Some nutritionists provide general guidance to individuals about eating to support good health.