A registered dietitian (RD) or registered dietitian nutritionist (RDN) is a credentialed practitioner who has, at least, completed a bachelor’s degree, a supervised practice program, the Commission on Dietetic Registration’s exam, and a state license. Both RD and RDN are protected titles, meaning only those who have completed the qualifications can use the titles. Nutritionist, however, is not a protected title, and anyone can claim it. There is no standardized training for nutritionists, and many nutritionist training programs are unregulated. Registered dietitians can provide preventative care and treat conditions like diabetes, eating disorders, gastrointestinal disorders, and many other medical conditions with medical nutrition therapy.