What We’re Getting Wrong About Mental Health
We’ve been taught to separate how we feel from how we eat.
Mood is often framed as something happening “in the mind” — something to manage, reframe, or push through. But the brain does not function in isolation from the body. It is built from it, fuelled by it, and constantly responding to it.
As Uma Naidoo writes in The Food Mood Connection,
“Food is not just calories; it’s information. It talks to your DNA and tells it what to do.”
That idea alone shifts the conversation. Because if food is information, then every meal is, in some way, influencing how the brain functions — including how stable, calm, or resilient we feel.
And yet, when it comes to mental health, the body is still often left out of the picture.
Mood is not just psychological — it’s physiological
What tends to get missed is that mood is not just psychological. It is also metabolic, inflammatory, and biochemical.
It is shaped by blood sugar stability, gut function, nutrient availability, and inflammatory signalling. When these systems are under strain, the brain reflects it.
Not metaphorically — biologically.
Blood sugar and the stress response
The brain depends on a steady supply of glucose. When that supply becomes unstable — through long gaps between meals, high-sugar intake, or erratic eating patterns — the body responds quickly.
A drop in blood glucose is interpreted as a stressor, activating the
Hypothalamic–pituitary–adrenal axis and triggering the release of cortisol and adrenaline.
What follows is often familiar:
a sense of anxiety or internal restlessness
irritability or low frustration tolerance
shakiness or difficulty concentrating
Research on reactive hypoglycaemia shows that these fluctuations can impair cognitive performance and increase anxiety-like symptoms.
In that context, what is often labelled as anxiety can, at times, be a physiological response to unstable fuel supply.
The gut and the brain are in constant conversation
Through the Gut–brain axis, the gut and brain are continuously communicating.
This happens via neural pathways such as the vagus nerve, through immune signalling, and through metabolites produced by gut microbes.
Research shows that:
around 90% of serotonin is synthesised in the gut
gut microbiota influence GABA and dopamine pathways
altered microbiome composition and increased intestinal permeability are associated with mood disorders and systemic inflammation
As Uma Naidoo writes,
“The gut and brain are intimately connected — what affects one directly affects the other.”
This is why digestive symptoms and low mood so often sit side by side — not coincidentally, but biologically.
Brain chemistry depends on what’s available
The brain relies on nutrients to produce
Neurotransmitters such as serotonin, dopamine, and GABA.
These processes depend on amino acids from protein, B vitamins (particularly B6, B12, and folate), minerals such as magnesium, zinc, and iron, and omega-3 fatty acids.
When these are insufficient — whether due to diet, digestion, or increased demand — the brain’s ability to regulate mood is directly affected.
Research consistently links low omega-3 intake with increased risk of depression, B-vitamin deficiencies with impaired neurotransmitter synthesis, and iron deficiency with fatigue, low mood, and reduced cognitive function.
So while mood feels emotional, it is also dependent on biological capacity.
Inflammation and mental health
Another layer increasingly recognised in research is inflammation.
Chronic low-grade inflammation has been associated with depression, fatigue, and reduced cognitive function. Elevated markers such as CRP, IL-6, and TNF-α are often observed in individuals experiencing low mood.
Diet plays a central role here.
Patterns high in ultra-processed foods and refined sugars are associated with increased inflammatory signalling, while whole-food, nutrient-dense dietary patterns are associated with reduced inflammation and improved mood outcomes.
Intervention studies, including those using Mediterranean-style diets, have demonstrated significant improvements in depressive symptoms through dietary change alone.
What this looks like in real life
When viewed through this lens, everyday experiences become easier to understand.
Skipping meals and then feeling anxious or shaky. Relying on sugar or caffeine for energy, only to experience a crash. Living with ongoing digestive discomfort and noticing that your mood feels flatter, more reactive, or less resilient.
These patterns are often dismissed or normalised. But they are not random.
They are physiological patterns with identifiable drivers.
Where nutritional therapy fits in
This is where nutritional therapy offers a different perspective.
Rather than separating mental and physical health, it looks at how systems interact and influence each other. The focus shifts from managing symptoms to understanding what might be driving them.
Support often begins with small, consistent changes — stabilising meals, supporting digestion, increasing nutrient density, and reducing inflammatory load.
Not as a quick fix, and not through restriction — but through supporting the body so that it can support the brain.
This is just the beginning
This is a starting point, not the full picture.
In the next posts, I’ll explore this further — looking more closely at how blood sugar influences anxiety and energy, how the gut shapes mood and resilience, and where to begin in a way that feels realistic and sustainable.
Because understanding the connection is one thing.
Knowing how to work with it is another.
A final thought
Your mood isn’t random.
And it isn’t separate from your body.
It is being affected — moment by moment — by what your body is experiencing.
With you, one Fika at a time,
Daniela | Nutrifika
This piece draws on the work of Uma Naidoo, alongside a broader body of research in nutritional psychiatry and the food–mood connection.
References
Naidoo, U. (2020) This Is Your Brain on Food. London: Little, Brown Spark.
Jacka, F.N. et al. (2017) ‘A randomised controlled trial of dietary improvement for adults with major depression (the SMILES trial)’, BMC Medicine, 15(23).
Marx, W. et al. (2021) ‘Nutritional psychiatry: the present state of the evidence’, Proceedings of the Nutrition Society, 80(3), pp. 1–15.
Cryan, J.F. and Dinan, T.G. (2012) ‘Mind-altering microorganisms: the impact of the gut microbiota on brain and behaviour’, Nature Reviews Neuroscience, 13(10), pp. 701–712.
