What Is A Registered Dietitian?

Updated: Sep 25

By Holley Samuel MEd, RD, LD, CPT

Reviewed by Erin Kenney MS, RD, LDN, HCP

Fact: Registered dietitians are the only state and nationally credentialed licensed nutrition professionals in the US.

Fact: Registered dietitians are the only professionals permitted to provide medical nutrition therapy in the clinical setting and individualized meal plans.

Registered dietitians are the most qualified to give nutrition advice across the board. If you have been present anywhere on the internet in this day and age, you may have noticed a lot of nutrition information circulating. Some of this information may seem far fetched while some is supported by research studies. Unfortunately, there appears to be no consistency in the profession responsible for spreading this information.

Doctors, dietitians, nutritionists, coaches, personal trainers, multi-level marketing representatives, professional and recreational athletes, and others seem to be behind sharing and declaring nutritional information across social media. It can be hard to navigate who is qualified to give health advice, and food and nutritional misinformation can negatively affect consumers' health, well-being, and economic status.

The standard of education required for the various titles or certifications in the United States:

Title or Certification

Education Required

Should you take nutrition advice from them?

Registered Dietitian (RD)

Licensed Dietitian (LD)

Registered Dietitian Nutritionist (RDN)

Licensed Dietitian Nutritionist (LDN)

(these are all equivalent and will collectively be referred to as “dietitian” in this table)

  • 4 year undergraduate degree completing didactic program requirements for nutrition & dietetics

  • Starting in 2024, a Masters degree is required

  • Apply and be matched to a 1200 hour post graduate accredited internship program in food service, community nutrition, and clinical nutrition

  • Pass Boards Exam

  • 75 hours continuing education required every 5 years to maintain credential nationally, with various hours required per state yearly in addition

Yes. This is the only nationally credentialed nutrition professional, and is the most qualified to give nutrition advice. Dietitians are also the only licensed professionals qualified to provide medical nutrition therapy (MNT) to people in clinical settings with specific medical conditions.

Many also specialize within the field by taking further boards exams and completing 1500-2000+ hours additional experience and yearly continuing education within the specialty, such as:

  • sports nutrition (CSSD)

  • renal nutrition (CSR)

  • geriatric nutrition (CSG)

  • pediatric nutrition (CSP)

  • oncology nutrition (CSO)

  • obesity and weight management (CSOWM)

  • pediatric critical care nutrition (CSPCC)


Licensed Nutritionist


Certified Nutrition Specialist


It varies per state. There is no national recognition of the title “nutritionist” (which is different than “registered dietitian nutritionist” or “licensed dietitian nutritionist”, see above), though in some states the title Certified Nutrition Specialist (CNS), requires formal education, training, examination and are granted the same or similar scope of practice as a dietitian (see above).

Some states require a degree in nutrition to be held in order to hold the title of nutritionist, but this is not nationally regulated and most states do not have any requirements to hold this title.

For example, in some states someone can have their PhD in nutrition and be called “nutritionist” while others can have no educational background in nutrition and be called “nutritionist.”

A dietitian can always do everything a nutritionist can do, but a nutritionist cannot usually do everything a dietitian can do.

If someone holds their Certified Nutrition Specialist (CNS) title or has their undergraduate degree in dietetics or nutrition, masters degree in nutrition science or nutrition education, or PhD in nutrition related sciences, they may be permitted to provide general nutrition education to the public. Whether or not they are allowed to provide individualized meal plans or nutrition therapy depends on the state.

If someone has completed an online or in person nutrition certification course such as Precision Nutrition, take advice with caution knowing they may not be the most qualified professional to provide nutrition advice, and these short certification courses are often limited and nationally unregulated in terms of providing consistent, accurate information. Individuals who have taken nutrition certification courses but do NOT hold the dietitian credential are not permitted to give individualized meal plans, prescribe supplements to treat medical conditions, or provide medical nutrition therapy in clinical settings.

If someone has no formal education in nutrition at all, do not take nutrition advice from them.

Health Coach

Wellness Coach


Health coaching certifications from organizations such as WellCoaches, ACE, Institute for Integrated Nutrition, Precision Nutrition, NASM, Health Coach Institute have set curriculums, usually an exam, and some continuing education depending on the program. There is not necessarily a consistent curriculum, one collective board exam, or consistent required continuing education though for the title of “coach” or “health coach” across the board uniting the title to meet a specific national standard.

Programs range from a few hours to several weeks in length, and some require prerequisites to attend such as an undergraduate degree in a related field while others do not.

A dietitian can do everything a health coach can do, but a health coach cannot do everything a dietitian can do.

Coaches are not permitted to give individualized meal plans, prescribe supplements to treat medical conditions, or medical nutrition therapy.

Some dietitians (see above) also participate in coaching certifications to continue their coaching skills education. These unique individuals are permitted to give individualized nutrition advice, but only if they also hold the dietitian credential.

Proceed with caution when heeding advice from coaches, as their educational background and qualifications vary widely.

Certified Personal Trainer (CPT)

Personal training certifications from organizations like ACE, ACSM, NASM, ISSA, and NCSF generally require the passing of an exam to maintain the certification, current CPR certification, and some also require prerequisites like holding an undergraduate degree in a related field.

Personal Trainers also typically are required to meet continuing education requirements yearly, which vary depending on the organization.

A dietitian cannot always do everything a personal trainer can do in the exercise department, but can do everything a personal trainer can do in the nutrition department. A personal trainer cannot do everything a dietitian can do in the nutrition department.

Personal trainers may give general nutrition advice, but are not permitted to give individualized nutrition advice, meal plans, or provide medical nutrition therapy in clinical settings. Personal trainers can provide training plans, in person training sessions, and exercise guidance.

Like with coaches, some dietitians (see above) also hold personal trainer certifications, and thus could give individualized nutrition advice and exercise plans. These unique individuals need to also hold the dietitian credential.

Other health care professionals (including, but not limited to, nurses, doctors, physical therapists, chiropractors, surgeons, naturopaths, veterinarians)

While the required educational background of these various health care professionals vary, many include up to a decade or more of required stringent and very heavily regulated formal education, boards exams, clinical practicum, and continuing education.

Generally speaking, most health care professionals outside of the dietitian credential (see above) complete very minimal nutrition education within these foundational formal educational programs. Unless they go on to seek out continuing education in nutrition as a speciality, they receive a small fraction of the specific nutrition education dietitians receive in their formal education and continuing educational requirements.

Dietitians are health care professionals within the health care system as a whole who specialize in nutrition.

One study showed that medical institutions across the US only offer on average 23.9 contact hours of nutrition education within their medical programs, which is lower than the 25 contact hours required by the National Academy of Sciences for medical professionals (such as medical doctor MD, or doctor of osteopathic medicine DO) and far lower than the thousands of hours required to become a dietitian (see above).

Most health care professionals outside of the “dietitian” credential (see above) may provide individualized medical advice within their scope of practice, and can provide nutrition advice, but they generally should refer to a dietitian for these services unless they have received more specific education on nutrition.

This article aims to clarify the level and degree of nutrition educational background among various people in the US giving nutrition advice. Registered dietitians are the most qualified people to provide nutrition information. Registered dietitians are the only qualified individuals to provide individualized meal plans and medical nutrition therapy in clinical settings.

Registered dietitians should be sought out as the experts in the field of nutrition, and other persons who have completed nutrition education should play a supporting role to distribute accurate and helpful nutrition information to the public within their scopes of practice. Nutrition information from all other persons not holding the credential of a registered dietitian should be heeded with caution, as misinformation around nutrition and health can be harmful.


  1. Adams KM, Lindell KC, Kohlmeier M, Zeisel SH. Status of nutrition education in medical schools. Am J Clin Nutr. 2006;83(4):941S-944S. doi:10.1093/ajcn/83.4.941S

  2. Institute of Medicine (US) Committee on Nutrition Services for Medicare Beneficiaries. The Role of Nutrition in Maintaining Health in the Nation's Elderly: Evaluating Coverage of Nutrition Services for the Medicare Population. Washington (DC): National Academies Press (US); 2000. 13, Providers of Nutrition Services. Available from: https://www.ncbi.nlm.nih.gov/books/NBK225306/