Nutrition, Gut Health and Fatigue

Lead Dietician and Nutritionist at Expand Health, Maryke Gallagher explains how the root causes of fatigue are often tied directly to nutrition.

July 31st, 2025

Understanding the root cause of your fatigue with lead dietician, Maryke Gallagher

Nutrition, Gut Health & Fatigue: What You Eat Could Be Draining Your Energy

By Maryke Gallagher, Lead Nutritionist at Expand Health

Feeling tired all the time, no matter how much you rest? While fatigue is complex and multifactorial, many of its root causes are tied directly - or indirectly - to nutrition. From nutrient deficiencies and inflammation to gut imbalances and poor mitochondrial function, your diet plays a central role in your energy levels.

Nutrients and Energy Production

The body relies on macro- and micronutrients to power crucial functions like oxygen transport, enzymatic reactions, DNA repair, immune balance and mitochondrial energy production. When your diet is lacking—or when stress, illness, or poor absorption interfere - your cells can’t produce enough energy to keep you going.

Some common nutrients and its link to fatigue

Iron deficiency. Required for oxygen transport and energy production.
Vitamin B12 & folate. Important for making red blood cells, DNA repair and activation of enzymatic processes for energy production.

Vitamin D: Plays a key role in mitochondrial function, has anti-inflammatory and immune modulating effects, involved in mood regulation and depression management. Often low in individuals suffering from chronic fatigue.
Magnesium: Involved in >300 enzymatic reactions including ATP production (the primary energy currency of cells)

Women, vegetarians, athletes, individuals with gut issues or chronic illness, and those on restrictive diets or recovering from gastrointestinal surgery are most at risk of deficiency. Genetics can also influence how well your body absorbs or utilises these nutrients. Understanding your unique genetic profile can assist in getting to the root cause of your chronic fatigue.

Gut Health, Inflammation & Fatigue

There’s growing evidence linking gut microbiome imbalances (dysbiosis) to chronic fatigue. A disrupted gut ecosystem can lead to systemic inflammation, compromised energy metabolism, and even neurocognitive symptoms or mood changes through the gut-brain-mitochondria axis - all of which increase fatigue.

What’s going wrong?

Reduced microbial diversity: Fewer beneficial strains means reduced short-chain fatty acids like butyrate, which are vital for energy production.
Leaky gut: Dysbiosis can also promote gut permeability that can trigger immune activation and inflammation. The production of inflammatory cytokines (proteins released by immune cells that cause inflammation) could contribute to fatigue by affecting motivation, serotonin levels and sleep. Chronic inflammation increases which damage mitochondrial membranes and enzymes and reduces the production of ATP.

How to Nourish for Energy

To support both gut and mitochondrial health, prioritise:

A plant-rich, anti-inflammatory diet rich in prebiotic fibres, deep coloured fruit, vegetables and plants that contain polyphenols such as flavanoids (tea, berries), curcumin (turmeric), resveratrol (grapes) and flavan-3-ols (cocoa), and other anti-inflammatory nutrients such as omega 3 and vitamin D
Foods with natural prebiotics and probiotics (e.g. berries, oats, fermented foods – if tolerated). Probiotics play an important role in gut health by improving the gut barrier, supporting the production of short-chain fatty acids and ensuring a balance between favourable and less favourable microorganisms in your digestive tract.
Nutrients like CoQ10, alpha-lipoic acid, L-carnitine, and magnesium

Note: While fermented foods are generally associated with positive gut health outcomes, it is not universally beneficial for everyone. Those with histamine intolerance, SIBO, or certain immune conditions may experience worsened symptoms and should use fermented foods cautiously.

Blood Sugar and Fatigue

Reactive hypoglycemia—a sharp drop in blood sugar—can leave you feeling weak, dizzy and fatigued. It’s often linked to insulin resistance, adrenal dysfunction, or high-carb meals without enough protein or fibre.

To support blood sugar balance:

Eat structured meals (meal timing) with protein, fibre and healthy fats.
Choose low-GI carbs (e.g. sweet potatoes, quinoa, oats).
Optimise your intake of magnesium, B-complex vitamins, inositol, and vitamin D.
Prioritise stress management and sleep.
Don’t forget: a healthy gut microbiome plays a powerful role in glucose regulation and insulin levels, thus lowering inflammation too.

Your Path to More Energy

Fatigue doesn’t have a one-size-fits-all solution. If you're feeling persistently tired, it’s worth exploring whether nutritional and lifestyle factors are at play. At Expand Health, our team can help you uncover the root cause and develop a personalised, sustainable plan to support your energy, mood and vitality.

📩 Ready to optimise your nutrition for better energy? Book a consultation with Maryke Gallagher or comprehensive genetics test with our nutrition team today.

WhatsApp us on +27 66 448 0238