What is Functional Nutrition?

Nutrition is a key factor in the development and progression of nearly all of the primary chronic diseases our world faces today, including cardiovascular disease, autoimmune diseases, diabetes, cancer, and neurodegenerative conditions like Alzheimer’s disease. Yet for people struggling with chronic health conditions, the broad and impersonal nutrition guidelines offered by our government and large medical organizations often fail to help.21

While the U.S. Dietary Guidelines offer a reasonable place to start with general suggestions such as “eat less than 10 percent of your calories as added sugars” and “vary your veggies,” these basic guidelines fail to account for the complex ways in which nutrition influences health and wellbeing.9

The growing field of functional nutrition is uniquely poised to fill the vital need for personalized, practical nutrition care for the millions of people in our society suffering from chronic health conditions.

Functional nutrition is a branch of functional medicine that takes an evidence-based, holistic, and personalized approach to optimizing one's diet to treat the root cause of illness, reverse chronic disease, and restore health. Read on to learn about how functional nutrition can help you heal your body and build vibrant health. 


Conventional vs. Functional Nutrition Care

The importance of nutrition in promoting health can be traced back to ancient Greece. Hippocrates is credited with saying, "let food be thy medicine, and medicine be thy food." However, dietetics as a healthcare specialty only progressed significantly in the 19th century when scientific advances enabled the discovery of vitamins.15

In the 20th and 21st centuries, we’ve witnessed the emergence of a new field of nutrition – functional nutrition – from the conventional dietetics paradigm. Conventional nutrition care, such as the type of nutrition care one is likely to receive in a hospital setting, is typically not very personalized. Conversely, functional nutrition is highly personalized, proactive, and preventive, accounting for the individual's unique nutritional needs, health concerns, and food preferences. 

Conventional nutrition care often adheres to government dietary guidelines, such as the U.S. Dietary Guidelines. These guidelines are often out of sync with the latest nutrition research. As a result, conventional nutrition recommendations frequently lag many years - or even decades - behind the most relevant and cutting-edge nutrition research. In contrast, functional nutritionists work to keep up with the latest research and weave it into clinical nutrition practice.

The Vital Role of Nutrition in Healthcare

Our bodies are constructed from and fueled by the foods we eat. Importantly, nutritional imbalances can cause or contribute to numerous chronic health conditions, including type 2 diabetes, neurodegenerative diseases such as Alzheimer’s disease, and gastrointestinal conditions such as irritable bowel syndrome (IBS).1, 11, 28

A recent review paper states, "the role of nutrition in chronic disease management is particularly crucial as diet is a modifiable risk factor for most chronic conditions that exist either as single conditions or in comorbid states." In other words, nutrition can powerfully impact chronic health conditions.22

Despite the vast importance of nutrition for preventing and correcting chronic disease and supporting optimal health, nutrition education in medical school is scanty. In addition, a typical 7-15-minute conversation with your doctor during your annual physical is unlikely to touch on nutrition. In other words, nutrition is not typically addressed in conventional medical settings. Fortunately, nutritionists and dietitians trained in functional nutrition are ideally suited to fulfill patients’ needs for evidence-based, personalized nutrition care.8

Principles of Functional Nutrition

Now that we’ve differentiated conventional versus functional nutrition care and highlighted the importance of nutrition in combating the chronic disease epidemic, let's discuss the principles of functional nutrition. 

Personalized Approach

Functional nutrition is founded upon a personalized, patient-centered approach. This personalized approach to nutrition considers factors such as the patient’s dietary history, food intolerances and preferences, and cultural considerations. 

Biochemical Individuality

As human beings, we all share particular nutritional needs. For example, we all need adequate dietary protein, vitamin B12, and calcium for our bodies to function. However, each of us also possesses unique biochemical traits that influence our nutritional needs. For example, some people thrive on higher carbohydrate diets, while others do best on a low-carb approach. No one-size-fits-all diet works for everyone, and a functional nutrition approach places biochemical individuality front and center. 

Holistic Perspective

In functional nutrition, we look at the body as an elegant array of systems that work together to create health rather than as separate systems (cardiovascular system, gastrointestinal system, etc.), each functioning in isolation. A functional nutritionist can take this holistic perspective and tailor dietary recommendations to address the body systems most significantly affecting a patient so that the body can function optimally. 

Food as Medicine and Therapeutic Foods

In functional nutrition, food isn’t just a source of energy – certain foods and dietary approaches can function as “medicine,” helping to repair and heal the body. Along these lines, functional nutrition approaches actively encourage the intake of certain therapeutic foods, such as fermented foods rich in probiotics, and fatty fish as a source of omega-3s. 

Nutrient-dense Eating

A functional nutrition approach emphasizes eating nutrient-dense foods. Nutrient density refers to the amount of micronutrients (vitamins and minerals) and phytochemicals in a food relative to its calorie content. High-nutrient-density foods supply abundant nutrients. Examples include red meat, fatty cold-water fish, berries, and cruciferous vegetables. This provides the critical nutrition “information” and building blocks that our bodies need to function optimally, and directly influences our genes through a process called epigenetics.  Low-nutrient-density foods provide lots of calories without micronutrients or phytonutrients. Examples include bread, pasta, chips, crackers, and "junk food." Low-nutrient-density foods are devoid of the nutrients we need, make us feel full, and perpetuate or worsen many chronic illnesses through a variety of pathways.

Functional Nutrition for Chronic Health Conditions

Functional nutrition approaches can aid in the management of a variety of health conditions. 

Heart Disease

Heart disease is currently the number one cause of death in the United States. Heart disease is a condition that is highly modifiable through nutrition, but perhaps not in the way you might think!6

While dietary saturated fat and cholesterol have long been demonized for their purported role in heart disease, the most current research indicates that this blame has been wrongly placed. While some people may need to limit their saturated fat intake to improve their cardiovascular health (oftentimes, genetic factors are at play here), dietary saturated fat and cholesterol are not the main nutritional factors driving heart disease for most people.3

Emerging research indicates that refined sugar and carbohydrate intake, blood sugar control, inflammation, and dietary antioxidant intake may be more important drivers of cardiovascular disease.27, 16, 29

A functional nutritionist can help you identify the nutritional factors to prioritize for your heart health so that you don’t unnecessarily limit your intake of certain healthy foods and can focus on the nutritional changes that matter most for your heart health.

Metabolic Syndrome, Prediabetes, and Type 2 Diabetes

Conventional nutrition recommendations for patients with metabolic syndrome, prediabetes, and type 2 diabetes are woefully outdated. It is well established that a diet high in refined carbohydrates and processed foods increases the risk of type 2 diabetes. Yet, the American Diabetes Association still advises diabetics to eat foods such as bread, pasta, and cereal, which are refined carbohydrates that cause spikes in blood sugar.27

Conversely, a functional nutrition approach to metabolic syndrome, prediabetes, and type 2 diabetes will often involve lowering a person’s total sugar and carbohydrate intake, and shifting the focus away from processed flour-based carbs towards low-glycemic whole-food carbohydrates that have less of an impact on blood sugar, such as root vegetables, non-starchy vegetables, and whole fruit. 

A functional nutritionist may also advise a patient to eat foods in a particular order (non-starchy veggies first, protein second, carbs third) to regulate the blood sugar response to a meal and work one-on-one with the patient as they track their blood sugar with a continuous glucose monitor (CGM) to identify which foods work best for their blood sugar.25, 7

Finally, some patients with type 2 diabetes may benefit from a very low-carb, high-fat ketogenic diet, in which case a functional nutritionist can help them safely implement it.14

Autoimmune Disorders

Conventional medicine has little to offer for managing autoimmune disorders besides pharmaceutical drugs. While there’s certainly a time and place for these medications, many patients with autoimmunity want to improve their health and quality of life, not just suppress their symptoms. Functional nutrition can support powerful improvements in health and quality of life for patients suffering from autoimmune disorders.

For a simple example, a gluten-free diet can help many people with autoimmune conditions because celiac disease and non-celiac gluten sensitivity frequently play a role in the autoimmune disease process.19

In addition, some patients with autoimmune disease may benefit from the autoimmune protocol (AIP) diet. This elimination diet removes foods that can trigger an immune response for 2-3 months to help calm the immune system; it also provides abundant nutrient-dense foods to support healing. Research shows that an AIP diet can help patients with several autoimmune conditions, including inflammatory bowel disease and rheumatoid arthritis.17, 20

Gut Health

According to a recent U.S. survey, over 60% of Americans struggle with at least one gastrointestinal symptom weekly, such as acid reflux, bloating, diarrhea, or constipation. Gut issues are no small matter, and they can be profoundly impacted by food.2 

A functional nutrition approach to gut disorders is highly individualized based on the gut disorder a patient is dealing with and their unique food sensitivities. For example, a patient with SIBO may do well on a short-term low-FODMAP diet while they pursue antibiotic or herbal SIBO treatment. In contrast, a patient with reflux may find that cutting out dairy and reducing refined carbohydrate intake improves their symptoms. 

Another important gut-related topic is intestinal permeability, often referred to as “leaky gut” in functional medicine. Increased intestinal permeability is a condition where the lining of the small intestine becomes more permeable than it should be. Normally, the cells lining the intestine are tightly packed together, forming a barrier that keeps harmful substances like bacteria and undigested food particles from passing into the bloodstream. However, when the lining becomes more permeable, these substances can leak through and cause inflammation in the body.  Intestinal permeability is a key underlying factor for a wide variety of health conditions and inflammatory issues. 

Mental Health

Food has a dramatic impact on mood. The relationship between food and mood may be mediated by the “gut-brain axis,” a two-way signaling system between the gut and brain. Via this system, inputs from the gut, such as gut bacteria and food, can influence the nervous system.24

Intestinal permeability and leaky gut plays a key role in mental health issues as well since this is linked to permeability of the blood-brain barrier, or BBB, (the cellular barrier that normally keeps substances in the blood out of the brain). BBB permeability, referred to as “leaky brain,” is implicated in multiple mental health conditions.12

With mental health conditions rapidly growing in prevalence, there’s never been a better time to focus on the gut-food-mood connection.13

A functional nutrition approach to mental health may include also optimizing your intake of crucial mood-supporting nutrients, such as omega-3 fatty acids and magnesium. It may also involve modifying your diet to promote healthier blood sugar control or removing gluten, a common trigger for mood disorders.18, 4, 23, 5

Balancing Hormones

Hormonal symptoms are common among patients seeking functional medical care. For example, many perimenopausal and menopausal women struggle with various unpleasant hormonal symptoms, including hot flashes and weight gain. Men may also struggle from symptoms related to abnormally low testosterone, such as fatigue, irritability, difficulty gaining muscle, and trouble with sex drive or erections. Functional nutrition approaches such as optimizing protein intake to support insulin sensitivity, strategically decreasing carbohydrate intake, and optimization of key nutrients may help.26

Functional nutrition approaches for patients with thyroid hormone imbalances may include optimizing dietary intake of iodine, zinc, selenium, and vitamin A, and ensuring sufficient calorie and carbohydrate intake.21 

Functional nutrition has applications in a wide variety of health conditions. But what exactly does it look like to work with a functional nutritionist? Next up, we’ll discuss the key components of a functional nutrition plan and what it is like to work with a functional nutritionist at The California Center for Functional Medicine (CCFM).

Key Components of a Functional Nutrition Plan

What does a functional nutrition plan look like? There are five crucial aspects of a functional nutrition plan:

  1. Dietary Recommendations. When working with a functional nutritionist, you’ll receive nutritional recommendations uniquely suited to your body and health goals. These dietary recommendations can include minor adjustments or large-scale changes, such as a targeted and therapeutic elimination diet. Dietary recommendations are based on the patient's health history, current health concerns, food preferences, and lab test results. Some nutritionists (such as our nutritionist at CCFM) may also offer meal planning services to patients. 
  2. Lifestyle Modifications. Diet and lifestyle are inextricably linked, so a functional nutritionist may also discuss lifestyle modifications with you. Examples of lifestyle modifications that might be covered include mindful eating strategies, stress reduction, exercise recommendations, and optimal timing of food intake and sleep.
  3. Nutritional Supplements. Many functional nutritionists are well-trained in the area of dietary supplements. Specific health concerns or lab results may warrant nutritional supplementation. At CCFM, our nutritionist always consults with our clinicians before recommending dietary supplements to ensure that your supplementation plan is targeted, appropriate for your needs, and appropriate based on your entire care plan. 
  4. Monitoring and Adjusting. Functional nutritionists recognize that patients' nutritional needs evolve. Therefore, you should plan to work with a functional nutritionist for at least several months so they can monitor your progress over time and adjust your nutrition plan accordingly. 
  5. Ongoing Support. A well-constructed functional nutrition plan should include ongoing support from your functional nutritionist. The process of improving and fine-tuning your diet takes time, so having close support from your nutritionist along the way is key. It is also really helpful to have the help of a functional medicine health coach to have the best success with lifestyle change. This is why we have built a comprehensive care team to help you. 

What It’s Like Working with a Functional Nutritionist

  1. At CCFM, you’ll meet with our functional nutritionist for an in-depth intake visit once you sign on as a new patient. Our nutritionist will ask you about your nutrition history, health concerns, and diet in this initial nutrition consultation. She will then put together a set of nutrition recommendations designed to get you started on the path to better health.
  2. Once your lab results (ordered in your initial consultation with one of our clinicians) are back, our nutritionist can also discuss the nutritional implications of the results and help you further fine-tune your diet. She may suggest you try an elimination diet, such as our Anti-Inflammatory Reset Diet, to jump-start your healing process.
  3. You will continue to work with our nutritionist throughout your journey at CCFM, since your nutrition plan will evolve throughout your health journey. Our nutrition experts are an integral part of the comprehensive care team that will be dedicated to your care. 

Functional Nutrition Case Studies

Names have been changed to protect the patient’s identity

Case Study #1

Patient: Sara 
Age: 23

Sara came to CCFM struggling with anxiety, bloating, frequent belching, and constipation. A typical day of food for her included cereal, toast, or a bagel with cream cheese for breakfast, PB&J for lunch, and various dishes cooked by her partner’s father (a restaurant owner) for dinner. 

Sara had never tried an elimination diet before coming to CCFM. After she completed her initial lab work ordered by her CCFM provider, we started her on an anti-inflammatory elimination diet that removed grains, dairy, legumes, concentrated sugars, and processed junk foods. The elimination diet was a big shift for her, but she was willing to give it a try! We provided her with numerous resources so that she’d feel confident implementing the elimination diet, including a detailed handout outlining the diet, ideas for grab-and-go foods she could eat when crunched for time, and a personalized sample meal plan with recipes. 

In addition, Sara. completed several days of food tracking in Cronometer, which revealed that she was under-eating calories and protein. We calculated calorie and protein targets for her and encouraged her to gradually work on increasing her calorie and protein intake. 

During the elimination diet, Sara observed a significant reduction in bloating and belching. Testing also revealed that she was positive for SIBO, so we made additional adjustments to her nutrition plan to aid her SIBO treatment, including making suggestions for optimizing her meal timing. 

Lab testing also indicated that Sara’s zinc level was low, so we worked on increasing her intake of zinc-rich foods. Her level of ferritin, the storage form of iron, was also low, so we provided recommendations for increasing iron, vitamin A, and copper intake (vitamin A and copper are required for proper iron metabolism). 

Once Sara had progressed through several weeks of SIBO treatment, she began to reintroduce gluten-free grains and legumes. She decided to hold off on reintroducing dairy because she suspected dairy products triggered some of her symptoms. I asked her to refrain from reintroducing gluten until she was further along with her gut treatment, since gluten is a common gut irritant. 

Sara has now reached a point where she eats a broad and flexible gluten- and dairy-free diet about 75-80% of the time, and has managed to maintain the improvements she’s experienced in her gut health. 

Case Study #2

Patient: Linda
Age: 57

Linda came to our practice struggling with multiple autoimmune conditions, including Grave’s disease, chronic idiopathic urticaria, an autoimmune condition affecting her platelets, and angioedema. She was frustrated and had not received the help that she needed from providers in the conventional medical space. 

After her Case Review with her doctor at CCFM, we started Linda on the autoimmune protocol (AIP), a nutrition plan designed to help people with autoimmune conditions lessen their symptoms and improve their quality of life. Linda. did a slightly modified version of AIP; for example, we kept goat and sheep milk dairy in her diet in moderation, along with white rice and eggs (dairy, eggs, and grains are usually removed completely on AIP). Over the next couple of months, Linda observed a significant improvement in urticaria on the modified AIP diet. 

Linda ate an AIP diet for three months as she progressed through her treatment protocols with her clinician, and then we began to reintroduce foods systematically, according to the AIP food reintroduction process, She was able to maintain the improvements she had gained in her health, including the improvement in urticaria, during the reintroduction process. She still strictly avoids gluten. At her most recent visit, Linda reported that while she still has some health concerns she’d like to work on, she is feeling very good overall! 

Case Study #3

Patient: Alan 
Age: 50

Alan came to CCFM dealing with anxiety, constipation, and stomach discomfort. His provider tested him for SIBO, which came back positive. We started him on a low-FODMAP diet, which immediately began to reduce his gastrointestinal symptoms. 

After a couple of months on the low-FODMAP diet and SIBO treatment prescribed by his provider at CCFM, he began to reintroduce foods with a moderate FODMAP content. After successfully reintroducing some moderate-FODMAP foods, he moved on to adding high-FODMAP foods. While some high-FODMAP foods still bother Alan’s gut, his reactions are much milder than they used to be. He is still working on improving his gut health with his CCFM provider and continues to experiment with reintroducing foods into his diet. 

Case Study #4: 

Patient: Jeremy
Age: 45

Jeremy has a complex health picture, including obesity, psoriasis, autoimmune thyroiditis, and eosinophilic esophagitis (EOE). When we met with him for his initial nutrition consultation, he expressed an interest in trying a ketogenic diet. However, he did not experience immediate success with the ketogenic diet and he had some difficulty adhering to the diet. He also had to navigate some additional food restrictions on the ketogenic diet, including dairy (which seemed to exacerbate nasal congestion and sinus issues) and eggs (both dairy and eggs can provoke EOE symptoms). 

After experimenting with a ketogenic diet off and on for over a year, Jeremy decided to try a low-carb diet as a “bridge” into the ketogenic diet. This approach proved successful. Recently, he has transitioned back to a ketogenic diet, is monitoring his ketones regularly, and has successfully maintained the protocol. His confidence in his ability to maintain a ketogenic diet has increased, and he plans to continue with the diet going forward. 

The Bottom Line on Functional Nutrition

Health begins in the gut and functional nutrition is the future of nutrition care. This personalized, patient-centered, holistic approach to nutrition care is uniquely poised to combat the chronic disease epidemic and help patients build optimal lifelong health.

At the California Center for Functional Medicine, functional nutrition is central to our functional medicine care model. Our functional nutritionist works closely with our clinicians to develop personalized nutrition plans for each of our patients that complement the functional medicine protocols developed by our clinicians. If you’re ready to take a holistic approach to your health that includes functional nutrition, you can learn more about our offerings here. In addition, we would be happy to answer any questions you have on a free discovery call with our New Patient Coordinator, Elise Gueda. 

Lindsay is one of the most intelligent and well rounded nutritionists I have ever worked with and known. She is so good with explaining things in a very easy to understand way. I value our time together so much and would highly recommend anyone work with her. 

Mara Kalow

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