These titles sound like they are the same qualified and trained professionals, but they are not.
A registered dietitian nutritionist (RDN) studies nutrition, food, and dietetics. All registered dietitians are nutritionists, but not all nutritionists are registered dietitians.
To be a registered dietitian, you must complete the following:
Currently, must complete a minimum of a bachelor’s degree through an Accredited Council for Education in Nutrition and Dietetics (ACEND) that is accredited Didactic Program in Dietetics (DPD) or Coordinated Program in Dietetics (CP).
Required to complete 1200 hours of supervised practice through an ACEND accredited Dietetic Internship.
Must pass a national examination that is administered by the Commission on Dietetics Registration.
Complete, submit, and receive approval for continuing professional educational requirements to maintain registration
To be a nutritionist, you must complete the following :
There are no such requirements to obtain a title of nutritionist.
No standards of education or training.
This means, anyone can use this title.
To be a RD or RDN you must adhere to the state laws and regulations. Only in a few states, will a nutritionist have restrictions on this title, which require certain levels of training and education. Outside of the handful of states, any person can be a nutritionist.
I hope this helps clarify any questions you had about these two different nutrition titles. If you have any additional questions about the differences, feel free to reach out and I will be more than happy to answer!