What is a Functional Dietitian Nutritionist?

Functional Dietitian Nutritionist Philosophy - Let food be thy medicine and medicine be thy food

“Food as medicine” is a concept that dates back to Hippocrates in ancient Greece, and it’s coming back around with a little help from us functional dietitian nutritionists!

A “functional dietitian nutritionist” is a term describing a holistic-minded registered dietitian-nutritionist (RDN) who helps people identify and address the root causes of chronic, long-standing health issues through a combination of clinical expertise, cutting-edge lab testing, nutritional counseling, and a “food as medicine” approach.

The primary goal and role of a functional dietitian nutritionist is to help people crack their unique health code and overcome unwanted chronic symptoms and conditions through leveraging the healing powers of food.

But first things first…

Dietitians vs nutritionists – how are they different?

Technically all dietitians are also considered nutritionists, but not all nutritionists are dietitians.

What is a dietitian?

A dietitian is a board-certified nutrition professional who has completed a bachelor’s degree in nutritional sciences, plus over 1200 hours of accredited, supervised dietetic internship practicum work.  In order to become a dietitian and obtain the “RDN” credential, we are also required to pass a national board exam.

In order to maintain the RDN credential, all dietitians must complete and submit a minimum of 75 hours of “continuing education units” (CEUs) logged every five years. This allows us to stay up-to-date on the latest evidence-based research and trends in the nutrition and health field, so we can best serve our clients and communities.

  • According to the Commission on Dietetic Registration (CDR), starting in January 2024, the minimum degree requirement to become a registered dietitian will change from a bachelor’s degree to a master’s degree.

What is a nutritionist?

The term “nutritionist” refers to someone who studies or practices in the field of nutrition.  There are no regulations, training, or licensure requirements for someone to call themselves a nutritionist, although most nutritionists do receive some form of training and education, either formally or informally.

  • It’s important to note that the RDN credential does not automatically make someone more qualified to help you. When I was struggling with leaky gut, I was already a registered dietitian but I worked in the field of eating disorders.  I ended up hiring a holistic functional nutritionist to help me because I did not yet specialize in gut health, and I wanted to work with someone who would share my philosophy and understand what I was going through at the root-cause level.  I worked with a holistic functional nutritionist 1:1 for over a year, and I benefited a great deal from our time together!

What is functional nutrition?

Functional nutrition is a branch of nutrition which stems from the field of functional medicine.  It’s different from general nutrition or clinical nutrition in that it is more holistic, with an emphasis on dietary recommendations that will allow people to restore wholeness and live more optimally.

Functional nutrition vs clinical nutrition

In general nutrition or clinical nutrition, the main purpose of dietary interventions is to help people to be more clinically stable.  Often in general or clinical nutrition, the consequences of long-term health and wellbeing are not taken into account.  This is where functional nutrition comes in!

  • For example, in mainstream healthcare settings, patients with diabetes are offered and encouraged to consume a wide range of sugar-free desserts sweetened with chemicals like Splenda or aspartame.  These artificial sweeteners don’t raise blood sugar acutely, but they’ve been shown to negatively impact gut bacteria, increase sugar cravings, and amplify insulin resistance in long-term studies (1). Gut health, sugar cravings and insulin resistance are all factors well known to contribute to and amplify diabetes at the root-cause level.
    • In functional nutrition, our mission is to help people make food choices that will move them away from a state of chronic illness over the long-term. A functional dietitian nutritionist would discourage people from consuming artificial sweeteners that amplify or worsen their underlying chronic health condition at the root level.

Jenna Volpe Functional Dietitian NutritionistWhat does a functional dietitian nutritionist do?

Functional dietitian nutritionists and functional medicine practitioners look far beyond just acute symptom management or clinical stability!

  • We dig deep, think critically, and read between the lines to see the full picture of our clients’ health from a holistic, birds-eye lens.
  • We assess what needs to happen from a nutrition standpoint to move someone completely away from a state of dis-ease, towards a state of balance, harmony and wellbeing of mind, body and spirit.
  • We understand that no two people are the same, so every client will likely get their own unique customized nutrition plan and supplement protocols based on a variety of factors when working with a functional dietitian nutritionist!
  • We leave no stone unturned…

A functional dietitian nutritionist also has access to cutting-edge information and testing that bridges the gaps between clinical and holistic health!

Functional nutrition testing

In functional medicine and functional nutrition, we’re able to order and interpret cutting-edge tests that allows us to understand what’s going on from a root-cause standpoint.

From there, we can provide our clients with exceptionally customized recommendations and individualized guidance around nutrition, supplements, and lifestyle habits which will allow and support natural healing over time.

Some of the most common functional nutrition lab tests we may run can include GI Mapping, DUTCH testing, micronutrient testing, the Mediator Release food sensitivity test, genetic testing, heavy metal tests, and more.

What does a functional dietitian nutritionist doAdditional services offered by functional dietitians / functional nutritionists

Aside from ordering functional nutrition lab tests, a functional dietitian / functional nutritionist may also provides clients with clinical nutrition assessment, medical nutrition therapy recommendations, complementary alternative medicine consultation, motivational interviewing, nutritional counseling, and coaching.

A functional dietitian nutritionist essentially serves as the compass or GPS, coaching and guiding our clients along a path which will allow them to access new levels clarity, “connecting the dots” and supporting their health from a multi-dimensional lifestyle change standpoint.

We understand that everything in the mind and body is connected. We aim to help our clients restore balance, especially in the following areas of focus:

  • The gut and microbiome (all health and all disease begins in the gut!)
  • The thyroid and endocrine system
  • The reproductive system
  • Mental health and the nervous system
  • The adrenals
  • The blood vessels

How to become a functional dietitian nutritionist

In order to become a functional dietitian nutritionist, the first step is to become a registered dietitian!  This entails getting a degree in nutritional sciences, followed by applying for and completing an accredited dietetic internship and sitting for the board exam.  This entire process can take anywhere from three to five years or longer.

For those who are already registered dietitians, the next step to becoming a functional dietitian nutritionist is to gain continuing education and experience in the field of functional nutrition/functional medicine!  You may want to consider applying to work for a functional nutrition or functional medicine clinic near you or virtually.

Resources and continuing education for functional dietitian nutritionists

Below are some wonderful ways to get continuing education and additional support in the world of functional nutrition!


A functional dietitian nutritionist is a fusion between a registered dietitian and a holistic nutritionist.  We are highly trained from a clinical nutrition standpoint as well as from a holistic, integrative, functional medicine perspective so that you can get the best of both worlds.

Working with a functional dietitian nutritionist is a fabulous way to address and resolve your unwanted symptoms of chronic illness head-on, especially when related to gut health. Going this path will likely save you many years of suffering and frustration.

If you’re on a healing journey and would like to be supported holistically from someone who has gone before you, feel free to apply for a complimentary connect call here!