In plain English
The registered dietitian credential - RD, or RDN for registered dietitian nutritionist - requires an accredited academic program, a supervised practice requirement of around a thousand hours, and a national examination. Most states licence or certify the profession on top of that.
Nutritionist is a different matter. In some states the title is regulated and in others anyone may use it, so it is not a reliable filter for a clinical audience. The registered credential is.
Dietitians are the profession responsible for medical nutrition therapy - the nutrition side of diabetes, renal, oncology, paediatric and critical care - and they sit on the care teams of hospitals, dialysis units and long-term care facilities as well as in outpatient practice.
Training and credentials
An accredited dietetics program, a supervised practice requirement, the national registration examination, and state licensure or certification where it exists.
| Letters | What they mean |
|---|---|
| RD | Registered dietitian. |
| RDN | Registered dietitian nutritionist - the same credential, newer wording. |
| LD, LDN | The state licence, where a state issues one. |
Where they practise
Hospitals and health systems, dialysis centres, long-term care, outpatient and private practice, public health and nutrition programs, food service and industry.
Registered dietitians on the public record
Counted from what providers file about themselves, with suppression applied before anything is counted, refreshed 2026-10-05. Names, specialties and practice locations are public; work email and phone are for signed-in customers.
| State | On record | With work email | With practice phone |
|---|---|---|---|
| California | 8,132 | 2,352 29% | 8,132 |
| Texas | 6,155 | 1,492 24% | 6,155 |
| New York | 5,472 | 1,410 26% | 5,471 |
| Florida | 4,057 | 984 24% | 4,057 |
| Pennsylvania | 3,594 | 1,149 32% | 3,593 |
| Illinois | 3,289 | 1,089 33% | 3,288 |
| North Carolina | 3,180 | 1,006 32% | 3,180 |
| Ohio | 2,894 | 1,062 37% | 2,893 |
Closely related, and where to find them.
Closely related
- Endocrinologist Hormones, glands and metabolism - and why diabetes care reaches far beyond the specialty.
- Nephrologist Kidney medicine and dialysis - and not to be confused with urology.
Find them
- Registered dietitians list counts by state, the fields a record carries, a sample record.
- All professions every profession - dental, pharmacy, therapy, behavioural health - and the organizations behind them.
- Certified dialysis centres, where dietitians are on the team
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