Understanding the Registered Dietitian (RD) and Registered Dietitian Nutritionist (RDN) Credentials
For many aspiring nutrition professionals and individuals seeking qualified dietary advice, the distinction between an RD and an RDN can be confusing. However, it is a straightforward matter. The Commission on Dietetic Registration (CDR), the credentialing agency for the Academy of Nutrition and Dietetics, introduced the optional RDN credential in 2013 to better reflect the full scope of dietitians' work, which includes both dietetics and nutrition. This was a strategic move to help clarify the credentials for the public and other healthcare professionals who might not be fully familiar with the term 'dietitian'. As a result, a practitioner can choose to use RD or RDN—they are interchangeable and require the exact same path to certification and maintenance.
The Path to Becoming an RD or RDN
Becoming a registered dietitian is a rigorous process designed to ensure a high level of expertise. The requirements are identical for those who choose to use the RD or RDN designation. According to the CDR, the process involves several critical steps:
- Education: As of January 1, 2024, candidates must hold a minimum of a master's degree from an accredited institution. The degree must be in nutrition, dietetics, or a closely related field and include specific coursework approved by the Accreditation Council for Education in Nutrition and Dietetics (ACEND).
- Supervised Practice: Applicants must complete a supervised practice program, often called a dietetic internship. These internships require at least 1,000 hours of hands-on training in various settings, including clinical, food service management, and community nutrition.
- National Examination: After completing the academic and practical requirements, candidates must pass a national registration examination administered by the CDR.
- Continuing Education: To maintain the credential, all RDs and RDNs must complete at least 75 hours of continuing professional education every five years.
- State Licensure: In most states, dietitians must also obtain a state license to practice legally, a process that is separate from the national certification.
Why the Optional Credential? The Public Perception Factor
Historically, the public has a varying understanding of the terms 'dietitian' and 'nutritionist.' While some may view them as synonymous, many assume a nutritionist title signifies a lower or less-regulated standard. While all registered dietitians are also nutritionists, the reverse is not true. The title 'nutritionist' is largely unregulated, and anyone can use it, regardless of their education or training. The CDR's decision to offer RDN as an option was partly a response to this confusion, helping to instantly communicate the high level of training associated with the credential.
Comparison Table: RD vs. RDN vs. Unregulated "Nutritionist"
| Feature | Registered Dietitian (RD) | Registered Dietitian Nutritionist (RDN) | Unregulated "Nutritionist" |
|---|---|---|---|
| Crediting Body | Commission on Dietetic Registration (CDR) | Commission on Dietetic Registration (CDR) | None (Varies by individual) |
| Core Meaning | Signifies a highly-trained food and nutrition expert | Identical meaning to RD; emphasizes nutrition | Varies widely; no standardized meaning or training |
| Education Required | Master's degree from an ACEND-accredited program (as of 2024) | Master's degree from an ACEND-accredited program (as of 2024) | None required to use the title |
| Supervised Practice | Mandatory 1000+ hour dietetic internship | Mandatory 1000+ hour dietetic internship | Not required |
| Exam Required | National CDR examination | National CDR examination | Not required |
| Legally Protected Title | Yes, legally protected | Yes, legally protected | No, not legally protected in most states |
| Medical Nutrition Therapy | Can legally provide MNT | Can legally provide MNT | Cannot provide medical nutrition therapy |
Conclusion: Choosing Between RD and RDN
Ultimately, the choice between using RD and RDN is a matter of personal preference for the professional, with no bearing on their qualifications, skill, or scope of practice. The core requirements, established by the CDR, ensure that anyone holding either title has met the same high standards of education, training, and examination. For the public, recognizing either credential is the key to identifying a truly qualified nutrition expert capable of providing evidence-based advice and, if necessary, medical nutrition therapy. Choosing a practitioner with either the RD or RDN credential guarantees that you are working with a food and nutrition professional who has completed the most rigorous training in the field. For further details on the credentials, you can visit the Academy of Nutrition and Dietetics at eatrightpro.org.
