You may be wondering what defines true expertise in nutrition.

Perhaps you have heard the terms “nutritionist” and “dietitian” and are confused by what they mean.

This article reviews the differences between dietitians and nutritionists, what they do, and the education required.

It focusses on definitions and regulations in the United States and addresses international ones only to a small degree.

In the United States and many other countries, a dietitian is a board-certified food and nutrition expert. They are highly educated in the field of nutrition and dietetics — the science of food, nutrition, and their impact on human health.

Through extensive training, dietitians acquire the expertise to provide evidence-based medical nutrition therapy and nutritional counseling tailored to meet an individual’s needs.

They are qualified to practice across a span of settings, including hospitals, outpatient clinics, research institutions, or local communities, to name a few.

Degrees and credentials required

To earn the credentials of Registered Dietitian (RD) or Registered Dietitian Nutritionist (RDN), a person needs to complete the criteria set forth by governing bodies like the Academy of Nutrition and Dietetics (AND) in the United States or the Dietitians Association of Australia (1, 2).

Additionally, in some countries, people may earn the title of “registered nutritionist,” which is synonymous with “registered dietitian” and requires certification from a governing body.

These are professional organizations that oversee the field of dietetics in their respective countries.

To clarify, the credentials of RD and RDN are interchangeable. However, RDN is a more recent designation. Dietitians can choose which credential they would rather use.

To earn these credentials, dietitians-to-be must first earn a bachelor’s degree or equivalent credits from an accredited program at a university or college.

Typically, this requires an undergraduate science degree, including courses in biology, microbiology, organic and inorganic chemistry, biochemistry, anatomy, and physiology, as well as more specialized nutrition coursework.

As of January 1, 2024, all dietetics students must also hold a master’s degree to qualify for their RD board examination in the United States (3).

In addition to formal education, all dietetics students in the United States must apply for and be matched with a competitive internship program accredited by the Accreditation Council for Education in Nutrition and Dietetics (ACEND).

Similar internships may be required in other countries.

Internships typically expose the student to 900–1,200 unpaid supervised practice hours across the 4 domains of practice, with careful adherence to competencies, or specific areas of study, complemented by in-depth projects and case studies outside of those hours.

Furthermore, the student must usually pass an exit exam mirroring the content of the board exam before completing the internship. The successful completion of these requirements qualifies them to take a board examination.

Finally, a dietetics student who passes the board exam in their respective country can apply to become a registered dietitian.

Licensure

Earning dietitian credentials requires national board certification. What’s more, many states, such as Texas, California, and Nebraska, require that dietitians be licensed in order to practice (4).

The process of licensing sometimes has additional requirements, like passing a jurisprudence exam. This is meant to ensure that dietitians practice under a code of conduct to protect public safety.

The dietitian must also continue their professional development by completing continuing education credits, which helps them keep up with the ever-evolving field.

Types of dietitians

There are four main domains of practice for dietitians — clinical, food service management, community, and research.

Clinical dietitians are those who work in an inpatient hospital setting. Outpatient dietitians may also work in a hospital or clinic, but they work with people who aren’t admitted to inpatient care and are usually less ill.

Both inpatient and outpatient dietitians provide support to the medical team to treat many acute and chronic illnesses. Dietitians in long-term care facilities may also supervise the nutrition of people with serious conditions that require ongoing care.

They follow standards of practice and detail a person’s medical history and current status, including lab work and weight history. This allows them to assess acute needs, prioritizing life-threatening conditions.

Inpatient and outpatient dietitians also provide nutrition education to people with specialized needs, such as those newly out of surgery, in cancer treatment, or diagnosed with chronic illnesses like diabetes or kidney disease.

In the outpatient setting, they give more in-depth nutritional counseling working towards a nutrition-oriented goal.

Dietitians may also work in other settings like research hospitals, universities, or food service management.

They can advocate for public policies and provide expertise in the community setting, such as school districts or public health organizations like Women, Infants, and Children (WIC).

Food service management dietitians oversee the production of nutritionally adequate food that meets food safety guidelines within a large organization, such as a school district or military base.

A community dietitian can help design and implement programs aimed at populations instead of individuals, such as community cooking initiatives or diabetes prevention interventions. They can also advocate for public policies with a focus on nutrition, food, and health issues.

Research dietitians typically work in research hospitals, organizations, or universities. They operate within a research team headed by a primary investigator and carry out nutrition-focused interventions.

Once dietitians have earned their credentials and are working in the field, they can go on to specialize in a particular subcategory, such as pediatrics or sports dietetics.

Finally, dietitians may also run private practices to provide services like nutritional counseling.

They may additionally teach in an academic or research institution or write about nutrition-related topics. Others may work as health and nutrition experts in media or as public speakers.

Conditions dietitians treat

Dietitians are qualified to manage nutrition therapy across a span of acute and chronic conditions. The type of conditions they treat depends most on the setting of their practice.

This means that they can treat nutrition problems that may arise from cancer or its treatment, as well as work with a client to prevent the onset of diabetes.

In hospitals, they treat a range of people, such as those who are clinically malnourished, as well as those who require nutrients via feeding tubes.

Dietitians also treat people undergoing bariatric (weight loss) surgery or those with kidney issues, as these individuals can have many nutritional restrictions and benefit from individualized care to fully meet their bodies’ needs.

Eating disorder dietitians have usually acquired additional training or education to treat this population. They work with a team of psychotherapists and doctors to help individuals recover from these disorders (5).

Eating disorders include chronic starvation (anorexia nervosa) or binging and purging (bulimia) (5, 6).

Sports dietitians specialize in optimizing nutrition for enhanced performance in athletes. These dietitians may work in gyms or physical therapy clinics, as well as with a sports team or dance company (7).

Summary

Dietitians can apply their expertise across a broad range of settings, such as hospitals, research institutions, and sports teams. They may prescribe nutrition therapy to help treat or prevent acute and chronic illnesses.

In some countries, people may translate their title as “nutritionist” rather than “dietitian,” though their educational background closely resembles that of a dietitian.

However, in the United States and other countries, a nutritionist is a person with an interest in nutrition and diet. There is no legal precedent for this term, so anyone can call themselves a nutritionist.

As a nutritionist has no legal standing in the United States, there is no code of conduct or standards of practice established to describe what they do.

They may apply their interest in nutrition to anything from running a food blog to working with clients.

However, because uncredentialed nutritionists typically lack the expertise and training for medical nutrition therapy and nutrition counseling, following their advice could be considered harmful (8).

Further, nutritionists in the United States don’t have to abide by a code of conduct, which are designed to protect the public and avoid conflicts of interests in promoting haphazard supplements or food products (8).

Degrees and credentials required

In the United States and many other countries, no degrees or credentials are required to be a nutritionist. You simply need an interest in the field.

However, alternative education and certifications may earn someone the title of Certified Nutrition Specialist (CNS).

Those with CNS credentials are health professionals like nurses or doctors with advanced health degrees who have sought out additional coursework and completed supervised practice hours, as well as passed an exam overseen by the American Nutrition Association.

Unlike RDs, CNSs do not prescribe nutrition therapy, though they can oversee community nutrition education programs.

Conditions they treat

In the United States, nutritionists have no legal standing to treat health conditions. Giving nutrition advice without the proper knowledge and training can be harmful, especially when counseling those with health conditions.

Moreover, those without credentials may see clients who seek approaches to nutrition that are outside the scope of traditional medicine.

However, this is typically less evidence-based, which may pose a health risk.

Summary

In the United States, “nutritionist” is a term that carries no legal meaning. Therefore, anyone can call themselves a nutritionist. Yet, alternative education and certifications may grant titles like Certified Nutrition Specialist.

Dietitians are credentialed, board-certified food and nutrition experts with extensive training and formal education.

Depending on where they live, dietitians may also need to meet additional requirements to be licensed to practice.

Dietitians can apply their expertise across a range of settings, including hospitals, academic institutions, and food service management. Some specialize in working with specific populations, such as children, athletes, or those with cancer or eating disorders.

Meanwhile, in many countries, including the United States, the term “nutritionist” carries no legal meaning. Thus, anyone can call themselves a nutritionist.

Some people seek out alternative qualifications and training, but not all training programs promote recommendations based on scientific research.