There is a lot of confusion around the terms dietitian, nutritionist, registered dietitian (RD), and registered dietitian nutritionist (RDN). Put that together with constantly changing diet recommendations from the media and it’s no wonder that people aren’t sure who to trust when it comes to nutrition advice. In this post, I’m going to attempt to clear up some of that uncertainty and give you an overview of what dietitians do.

Let’s start out with the basics: what is a dietitian, and how is a dietitian different from a nutritionist? To become a registered dietitian one must take a specific set of academic classes, complete at least 1200 supervised practice hours during the “dietetic internship” (programs are usually about a year long), and pass a national qualifying exam. A dietitian may use the title registered dietitian (RD) or registered dietitian nutritionist (RDN) depending on personal preference; the qualifications are the same. Dietitians must also regularly take continuing education courses to maintain their licenses. Many nutrition-related jobs such as hospital, clinic, and consultant positions require official licensure as an RD/RDN. By contrast, anyone who offers nutrition advice can use the title “nutritionist”. There are no official requirements and no national credentialing board to ensure that nutritionists are qualified and up to date with current practices.

I currently work as a clinical dietitian at a hospital run by the San Francisco Department of Public Health. For each unit of the hospital that I serve, I am part of an interdisciplinary team (IDT) consisting of a physician, several nurses, speech therapist, activity therapist, social worker, and sometimes a psychiatrist. We meet daily to review our patients and talk about how to provide the best care. As the dietitian, it is my responsibility to  assess nutritional status through anthropometric, biochemical, and clinical measures and determine the most appropriate diet to fit an individual’s needs.

When I get a new patient, the first thing I do is read the doctor’s last progress note and talk to the IDT to figure out what his or her major medical issues are. I then look at the weight trend, recent labs, and medications. When I talk to the patient, I ask them about their usual dietary habits, preferences, and any food allergies. I calculate their energy needs (how many calories, how much protein, and how much water they should consume each day) and use all of this information to recommend a diet plan.

Helping patients with weight management isn’t all that clinical dietitians do. Some of the most common medical conditions that I get consulted for are diabetes, kidney disease, and liver issues (ranging from fatty liver to cirrhosis). For example, people who have chronic kidney disease (CKD) often need to reduce the amount of protein and salt that they eat. If kidney function declines significantly, they may also need to restrict potassium (found in many fruits and vegetables) and phosphorus (found in animal products and as an additive).

A big part of my job is also parenteral (intravenous) feeding and enteral (tube) feeding. When an individual is unable to eat food by mouth, we feed them by providing nutrients directly into the veins or through a tube that goes into the stomach or small intestine. To ensure that a patient is meeting their nutritional needs through this method of feeding, I calculate his or her caloric requirements and determine the most appropriate formula and rate of administration. I then assess tolerance of the feeding by closely monitoring markers such as weight, labs, and gastrointestinal comfort.

Clinical dietetics is just one small part of what dietitians are qualified to do. Other career options include work in private practice, food service, research, workplace wellness, sports nutrition, public health food science, technology, and more. It’s an exciting time to be in the nutrition field; personalized nutrition is taking off and we are discovering more each day about how to promote health through food. If you have any further questions or are interested in pursuing a career in nutrition and dietetics, leave a comment below. I’m happy to help answer your questions and point you in the direction of additional resources!

What Is a Dietitian, Anyway?