By Dr. Corrinne Giles & The SABI

Fatigue isn’t just an inconvenient side effect of a busy life. It’s your body’s alarm system, flashing a warning that something is off-balance. You might think it’s due to poor sleep or stress - and often, it is - but what if the real culprit is hiding in plain sight? On your plate.

As a medical doctor and registered dietitian, I’ve seen countless patients chasing quick fixes for their exhaustion: another cup of coffee, a sugary snack, skipping meals to “power through,” or loading up on protein shakes. But the truth is, these habits can create a vicious cycle, making fatigue worse over time. Understanding the science behind energy metabolism reveals one simple fact: food isn’t just fuel - it’s information for your cells.

In this article, we will dismantle the most pervasive myths about food and energy and explore how smart nutrition can help combat burnout from the inside out.

Myth #1: "Coffee Is the Ultimate Energy Fix"

It’s the go-to solution when we feel drained. But here’s the biological reality: caffeine doesn’t create energy - it masks your body’s exhaustion signals by blocking adenosine, a neurotransmitter that builds up in your brain to promote sleep. While this trick can temporarily improve alertness, it comes at a cost.

Chronic excessive caffeine intake (more than 400 mg per day, or approximately four cups of coffee) may contribute to elevated cortisol levels in some individuals and disrupt circadian rhythm regulation, particularly when consumed later in the day.

This can negatively impact sleep quality, even in individuals who fall asleep easily, by reducing the duration and depth of restorative sleep stages. As a result, a cycle of dependency may develop, contributing to increased fatigue over time.  

A Smarter Approach:

• Green Tea contains less caffeine and pairs with L-theanine, an amino acid that promotes calm focus without the jittery crash. Research published in Nutrients (2016) found that L-theanine improves attention and reduces stress-related symptoms, making green tea a gentler, more balanced alternative to coffee. 

• Water: Dehydration, even at just 1-2%, can impair cognitive function and mood. Often, that “afternoon slump” isn’t hunger or fatigue - it’s dehydration. Aim for 2–3 litres of water daily, adjusting based on activity levels.

Myth #2: "Carbs Are the Enemy—or the Instant Energy Hero"

Carbohydrates have been unfairly vilified in recent years, but not all carbs are created equal. Refined carbohydrates (white bread, pastries, and sugary snacks) spike your blood sugar quickly, triggering a surge of insulin to bring it down. This rapid rollercoaster results in the infamous "sugar crash," leaving you more fatigued than before.

However, carbohydrates are your brain’s primary fuel source. The key is choosing the right type.

The Science of Slow-Release Energy:

• Low Glycaemic Index Carbohydrates rich in Fibre: The fibre found in whole grains, legumes, vegetables and fruits help slow digestion, providing a slower release of glucose into the bloodstream. Furthermore, a review published in The American Journal of Clinical Nutrition 2002 demonstrated that low-glycaemic index (GI) diets improve energy levels and reduce fatigue in both healthy individuals and those with metabolic conditions.

• Prebiotics: Present in foods like onions, garlic, leeks, asparagus, lentils, chickpeas.This non-digestible food ingredient that promotes the growth of beneficial microorganisms in the intestines, feeds your gut microbiome and promotes the production of short-chain fatty acids like butyrate, which have been linked to improved metabolic health and sustained energy. 

• Pairing Carbs with Healthy Fats or Protein also slows digestion and absorption, keeping energy levels more stable.  Examples include: toast with avocado and / or eggs or overnight oats (using rolled or steel cut oats) with chia seeds and plain Greek yogurt, or fruit with nut butter. 

Small tweaks like choosing sourdough or wholegrain over white bread, adding a drizzle of extra virgin olive oil to pasta instead of a creamy sauce, and swapping white potatoes for sweet potatoes can make carbs more gut friendly and healthier.

Myth #3: "Skipping Meals Helps You Stay Sharp"

Intermittent fasting has its place in metabolic health, but skipping meals indiscriminately, especially when under stress, can backfire. Your brain consumes about 20% of your body’s energy, primarily in the form of glucose. When that supply dips, cognitive functions like memory, concentration, and decision-making may suffer.

Skipping meals may trigger cortisol release in some individuals. Here the body perceives the skipped meal as a stressor which in turn may compound feelings of fatigue and anxiety. 

There is a growing body of research supporting the idea that intermittent fasting (IF), particularly time-restricted eating (TRE) like the 16:8 method, may offer several health benefits. However, the effects of intermittent fasting can differ between men and women due to hormonal differences and how women respond to stress or fasting. 

If you're managing PCOS or insulin resistance, intermittent fasting may improve insulin sensitivity and reduce inflammation. However, women, who are more stress-sensitive, may benefit from a more cycle-aware approach - like a shorter eating window in the follicular phase (first half of cycle) and slightly longer eating window in the luteal phase (second half of the cycle).

Instead of skipping meals, aim for regular and balanced meals:

• Prioritise Protein, Healthy Fats and Fibre rich Carbs: 

• Healthy fats ~ Olive oil, nuts & seeds, avocado, oily fish). Foods rich in omega-3 fats have been shown to support brain health - improving mood and cognitive performance.

• Protein ~ eggs (+bonus choline for brain function), fish, poultry, soya, quorn, lean cuts of unprocessed red meat.

• Fibre ~ wholegrains, whole fruit and vegetables

• Regular Small Meals: For those prone to energy crashes, eating smaller, balanced meals every 3-4 hours can.keep energy levels stable..

Myth #4: "Sugary Snacks Are the Quickest Fix for Fatigue"

When you're exhausted, your body craves quick energy, and sugar fits the bill - temporarily. But refined sugar floods your bloodstream with glucose, triggering a spike in insulin. This surge is followed by a drop in blood sugar and can lead to irritability, brain fog, and - you guessed it - more fatigue.

Energy-Sustaining Alternatives:

• Pairing Fruit with Protein and / or Fat: The natural sugars in fruits like berries or bananas are absorbed more slowly when combined with protein or healthy fats. For example:

• Banana with Nut Butter (healthy fat) on a rye cracker: On its own a banana provides quick natural sugars, but when combined with an additional fibre rich food and / or healthy fats, it offers a more sustained release of energy.

• Berries with plain Greek Yoghurt (+ live cultures) and a small handful of raw unsalted mixed nuts (healthy fats): The Greek Yoghurt with live cultures adds protein and probiotics, and the nuts adds sustained energy. The berries provide a rich source of antioxidants.

Myth #5: "The More Protein, The More Energy"

While protein is crucial for muscle repair, hormone production, and immune function, it’s not your body’s primary energy source. In fact, relying heavily on protein without enough carbohydrates can make you feel sluggish, as protein is less efficient at being converted into glucose.

The Balance That Matters:

• Protein + Fibre rich Carbs + Healthy Fats: This trio ensures that your body has sustained energy and the building blocks for repair (protein).  A 2008 review in The Journal of Clinical Endocrinology & Metabolism emphasizes the importance of a balanced macronutrient intake in improving metabolic flexibility, enabling your body to efficiently switch between different energy sources.

My Recommended Foods to Combat Burnout and Fatigue

When it comes to fighting chronic exhaustion, the goal isn’t just to “feel awake.” It’s about supporting your body at a cellular level - enhancing mitochondrial function (your cells’ powerhouses), reducing inflammation, and optimising hormonal balance.

A few examples of Nutrient-Dense Powerhouses:

• Leafy Greens (for example spinach, kale): Rich in magnesium and iron - key for energy metabolism. Iron deficiency, even without anaemia, is linked to fatigue.

• Avocados: Packed with healthy fats, fibre and B vitamins, essential for energy production and stress resilience.

• Berries: Rich in antioxidants, which combat oxidative stress - a hidden driver of fatigue. Oxidative stress  occurs when there is an imbalance between free radicals and antioxidants in the body. Free radicals are highly reactive molecules that can damage cells, while antioxidants are substances that neutralize these free radicals.

• Nuts & Seeds: mixed raw unsalted nuts, especially almonds, chia, flaxseeds provide protein, fibre, and omega-3 fatty acids, supporting both brain health and sustained energy.

• Greek Yoghurt with live and active cultures: A probiotic-rich food that promotes gut health, essential for nutrient absorption and immune function.

• Eggs: A complete protein source with choline, crucial for brain health and neurotransmitter function.

• Green Tea: rich in antioxidants and L-theanine.

Energy Isn’t Found in a Quick Fix

True, lasting energy doesn’t come from a cup of coffee, a sugar rush, or skipping meals to "push through." It’s the product of consistent, balanced nutrition that supports your body’s complex energy systems. Think of food not just as fuel, but as the raw material your body needs to create, store, and efficiently use energy.

If you’re feeling persistently drained despite making lifestyle changes, it’s worth consulting with a healthcare professional. Fatigue can also be a symptom of underlying conditions like thyroid disorders, anaemia, auto-immune conditions or chronic stress-related syndromes. Keep in mind that there is no one-size-fits-all solution, so it's essential to seek advice from a qualified healthcare provider.

About Dr. Corrinne Giles

Medical Doctor I Registered Dietitian | Certified Health Coach

Dr. Corrinne Giles is a medical doctor and registered dietitian with a passion for transforming lives through evidence-based nutrition and lifestyle interventions. With a background in practising medicine and with over 25 years experience in the field of nutrition,  she combines clinical expertise with a holistic approach to health. Her areas of focus include obesity and metabolic health, diabetes and prediabetes, women’s health (peri/menopause and PCOS), and gut-related disorders such as IBS, coeliac disease, diverticulosis, and microbiome imbalances. 

HORMONAL & PROUD

Created as a brand to help women navigate the toughest moments in pregnancy, childbirth, postpartum — and practically every stage of life –– The SABI aims to change the narrative around our hormones from one of taboo, embarrassment, and loneliness to awareness and pride. As more than a wellness brand, The SABI offers a carefully-crafted line of products to carry you through your hormonal journey, including rituals, supportive tools, and ancient herbal remedies that have been tested time and time again by women and now come backed by medicine. The SABI is a blend of science and nature conceived by women who have experienced the joys and deep struggles of bringing a child into the world, the pains of a heavy, difficult period, miscarriage, and difficulty conceiving.

We offer you an invitation to get to know your body and its cycles better –– an invitation to really understand what is going on inside. Learn to use your hormonal cycle to your advantage no matter your stage of life, and know that you can support and balance your hormone levels. Look for the right sources of information. Know that there is help, and know that you’re supported.

DISCLAIMER

The SABI blog and articles are not meant to instruct or advise on medical or health conditions, but to inform. The information and opinions presented here do not substitute professional medical advice or consultations with healthcare professionals for your unique situation.

REFERENCES

Benton, D., & Donohoe, R. (1999). The effects of nutrients on mood. Public Health Nutrition, 2(3a), 403-409.

Calder, P. C. (2015). Marine omega-3 fatty acids and inflammatory processes: Effects, mechanisms and clinical relevance. Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids, 1851(4), 469-484.

Dyall, Simon C.(2015) Long-chain omega-3 fatty acids and the brain: a review of the independent and shared effects of EPA, DPA and DHA.Frontiers in Aging Neuroscience, 7, 52. 21 Apr. 

Galgani, J. E., Moro, C., & Ravussin, E. (2008). Metabolic flexibility and insulin resistance. American Journal of Physiology-Endocrinology and Metabolism, 295(5), E1022-E1028.

Gómez-Pinilla, F. (2008). Brain foods: the effects of nutrients on brain function. Nature Reviews Neuroscience, 9(7), 568-578.

Jenkins, D. J. A., Kendall, C. W. C., Augustin, L. S. A., et al. (2002). Glycemic index: overview of implications in health and disease. The American Journal of Clinical Nutrition, 76(1), 266S-273S.

Kumari, A., K. G., R., Sudhakaran. V., A. et al. (2024) Unveiling the Health Benefits of Prebiotics: A Comprehensive Review. Indian Journal of Microbiology, 64, 376–388 

Longo, Valter D, and Satchidananda Panda. (2016). Fasting, Circadian Rhythms, and Time-Restricted Feeding in Healthy Lifespan. Cell Metabolism, 23(6), 1048-1059.

Nobre, A. C., Rao, A., & Owen, G. N. (2008). L-theanine, a natural constituent in tea, and its effect on mental state. Asia Pacific Journal of Clinical Nutrition, 17(S1), 167-168.

Popkin, B. M., D'Anci, K. E., & Rosenberg, I. H. (2010). Water, hydration, and health. Nutrition Reviews, 68(8), 439-458.

Sutton, Elizabeth F et al. (2018) Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. Cell Metabolism, 27(6), 1212-1221. 

Vauzour, D., Vafeiadou, K., Rodriguez-Mateos, A., Rendeiro, C., & Spencer, J. P. E. (2008). The neuroprotective potential of flavonoids: a multiplicity of effects. Genes & Nutrition, 3(3-4), 115-126.

White, David J et al. (2016) “Anti-Stress, Behavioural and Magnetoencephalography Effects of an L-Theanine-Based Nutrient Drink: A Randomised, Double-Blind, Placebo-Controlled, Crossover Trial.” Nutrients, 8(1), 53. 19 Jan. 

Youdim, K. A., & Joseph, J. A. (2001). A possible protective role of phytochemicals against age-related neurological diseases: functional and clinical implications. Proceedings of the Nutrition Society, 60(2), 171-175.