The generalist Registered Dietitian (RD) holds a bachelor’s degree in Nutrition. The American Dietetic Association maintains a list of registered dietitians in US. It seems that the title Nutritionist is not protected and have no governing bodies therefore anyone can use this title as they do not reflect training, experience, or adherence to a set of ethical principles. Please note that the title of Nutritionist is limited in some states. There are many Personal Trainers very knowledgeable in Nutrition and Sports nutrition. You can earn an associate degree as Registered Dietetic Technician too.