As a dietitian, I get this question a lot. Put simply all dietitians are nutritionists but not all nutritionists are dietitians. A dietitian has studied at university level for at least 4 years and has a medical degree. There are definitely some amazing nutritionists out there but also a lot of people calling themselves nutritionists or nutrition experts who have simply not studied extensively enough to put that next to their names. There are a few courses for nutritionists some of which are very basic and some are very comprehensive. If you are unsure of a person’s credentials ask them where they studied and for how long.