A nutritionist is a person who advises on matters of food and nutrition impacts on health. Different professional terms are used in different countries, employment settings and contexts — some examples include: nutrition scientist,public health nutritionist, dietitian-nutritionist, clinical nutritionist, and sports nutritionist.
Some use the terms “dietitian” and “nutritionist” as basically interchangeable. However in many countries and jurisdictions, the title “nutritionist” is not subject to professional regulation; any person may call themselves a nutrition expert even if they are wholly self-taught. In most US states, parts of Canada, Australia, and the United Kingdom, the term nutritionist is not legally protected, whereas the title of dietitian can be used only by those who have met specified professional requirements. One career counselor attempting to describe the difference between the two professions to Canadian students suggested “all dietitians are nutritionists, but not all nutritionists are dietitians.”