Functional nutrition: what does it mean? How does it relate to functional medicine? And what does it signify in the world of nutritional therapy?

Using food and nutrition to support human health isn’t new. Nutritional research, however, indicates that a food-first approach could be important for future healthcare.

Doctors are already seeing the connection between nutritional status and health. GPs now commonly test patients’ vitamin D and B12 levels.

Many have also called for medical students to receive nutrition training.

Others have advocated for GPs to work alongside registered nutritional therapy practitioners, who are trained in nutritional clinical practice.

What is functional nutrition?

Using nutrition to support health is sometimes referred to as ‘functional nutrition’.

A subset of functional medicine, it’s an approach used to optimise how the body is functioning, rather than cure a particular disease.

Kate Delmar-Morgan, head of clinics at the Institute for Optimum Nutrition (ION), says that functional medicine “is an evidence-based approach which [focuses] on addressing the underlying causes of symptoms and health issues” and “views the body as a whole, not taking one thing in isolation”.

Preventative healthcare

Dr Kirstie Lawton, an AfN-registered nutritionist and BANT-registered nutritional therapy practitioner, leads the functional nutrition module on ION’s Graduate Diploma in Integrative Functional Nutrition.

“When we talk about functional nutrition,” she says, “we’re using [the functional medicine] approach to determine how to optimise someone’s nutritional status.

“We’re looking at them as an individual, looking at which systems might not be functioning properly, where there might be imbalances in biochemical systems or in the microbiome, and correcting that using diet, lifestyle, and nutraceuticals [i.e. supplements, foods used therapeutically, and fortified foods].”

Delmar-Morgan adds: “We are not primary health care; we are practising preventative healthcare, looking to halt the driving factors of health issues; then we work with the tools of nutrition and lifestyle to try to help prevent further decline and restore balance and health.”

Seven interconnected systems

Key to this approach is the concept of the body as seven interconnected ‘systems’ of function.

Lawton says: “It’s what we call a systems biology-based approach, so we’re looking at their symptoms and determining which systems in their body are imbalanced, to find the root cause of illness.”

Lawton says practitioners review the function of all seven systems, as well as a person’s mental and emotional wellbeing to determine possible causes.

Antecedents, triggers and mediators

Practitioners also consider factors called ‘antecedents’ (e.g. genetics); ‘triggers’ (events such as illness, a course of antibiotics or trauma); and ‘mediators/perpetuators’ (a factor that causes symptoms to persist, such as someone with coeliac disease consuming gluten).

“Functional nutrition takes into account the fact that you are dealing with an individual,” says Delmar-Morgan.

“For example, if a client has high cholesterol, the aim is to find out why. We want to establish what is driving the high cholesterol for this particular person, so that this can be addressed rather than just applying a standard ‘low-cholesterol diet’.

“That person is completely different to the next person with high cholesterol… different genes, biochemical makeup, lifestyles — different everything.

“Without a functional medicine approach, they would just receive a protocol which simply applies to the general population, not tailored to that individual.”

Functional testing in clinic

Practitioners might carry out functional testing.

Lawton says: “If somebody came to the clinic with gut health issues, you would do a little bit of work to see if you could resolve that easily — something quite obvious, like remove gluten, egg or dairy — and if that wasn’t having any impact, you might want to run a functional stool test to get a picture of what’s going on in the gut.

“If you have someone come in with all sorts of hormonal issues — terrible periods, chronic pain, mood swings — you may want to run a hormonal test to try to identify what’s going on.”

The aim of functional nutrition

The aim of functional testing, says Delmar-Morgan, is different to that GPs may carry out where they are looking to diagnose or rule out a disease state.

“We are aiming to unearth nutrient and functional imbalances, which enable us to better understand what’s driving a client’s health issues,” she says.

For Delmar-Morgan, the aim of functional nutrition is to improve health for everybody. “Optimum nutrition is at the core of good health — that’s just fact. We need nutrients for our bodies to work properly.

“Particularly, there are people with reoccurring symptoms who go to the GP, are prescribed medication to alleviate the symptoms, but the problem doesn’t go away.

“If they don’t find that root cause, then they simply won’t get better; their health could just further decline. No one wants to live like that.”


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