Despite being related, these two professions have some important differences. Usually, people use both terms interchangeably. This is understandable given the close relationship between them. However, it is still important to make the distinction, especially if you want to get advice that is backed up legally.
Dietitian is an entity protected by law. The terms usually used are: “Registered Dietitian”, “Professional Dietitian”, or simply “Dietitian”. The title then can only be used by those who have been registered after formal education.
A dietitian has earned a Bachelor´s degree specializing in food and nutrition. Nutritionists who wish to obtain their license as a Dietitian must get such a degree.
Unlike dietitians, nutritionists are mostly allowed to work without a degree and are basically free from regulation. In the United States, some states might still require nutritionists to get an occupational license from a Board of Nutrition. Others will allow nutritionists to work without any degree, training, or previous experience.
The Academy of Nutrition and Dietetics says that registered dietitians must complete a formal education program approve by the Dietetics’ Accreditation Council for Education in Nutrition and Dietetics (ACEND). This program must include a practical component and coursework in areas including food and nutrition sciences, chemistry, computer sciences, microbiology, sociology, biochemistry, psychology, and economics.
Once the degree is completed, nutritionists can then register with the Commission on Dietetic Registration (CDR) to legally call themselves registered dietitians (RD).
In practical terms, a dietitian will use their knowledge to provide professional health advice on food and nutrition to enable healthy living. They are considered health professionals, unlike a nutritionist who can perform their craft without any professional degree. In order for you to identify a dietitian and tell them apart from a nutritionist, look for the letters R.D., P.Dt. or Dt.P. after their name.