Still Feeling Tired? Why Fibre Might Be One of the Foundations You Are Missing
Written by Dr. Alexis W. H. Chung
Nutritionist, Food Technologist & Functional Food Scientist
BSc Nutrition, PgD Human Nutrition, MSc Food Science, PgC Business, PhD Environment and Agriculture
When rest does not fix the tiredness
You thought you were just burnt out.
So you took a break. You slept in, cancelled plans, and tried to slow down.
But you still feel tired.
Not the normal kind of tired after a long day, but the heavy kind. The kind where your body feels slow, your brain feels foggy, and even simple tasks feel harder than they should.
When tiredness does not go away after rest, it can feel confusing. But fatigue is rarely caused by one thing. Our energy is shaped by a range of factors, including how we eat, sleep, move, and connect with others.
The Australian Government Department of Health describes this as a “domino effect”: physical activity, nutrition, and sleep all work together to support physical health, mental health, and wellbeing. Their guidance also highlights that food and nutrition can affect mental health and physical performance, while movement and sleep help support mood, stress, immune health, and recovery.¹
So where should we start?
One of the most overlooked foundations is fibre.
Fibre is more than “just for digestion”
Most people think of fibre as something that just helps you go to the toilet.
That is true, but it is only one part of the story.
Dietary fibre is also linked to gut microbiota, short-chain fatty acid production, inflammation, metabolic health, and potentially even mood and mental wellbeing. Some types of fibre act as food for beneficial gut bacteria. When these bacteria ferment fibre, they produce short-chain fatty acids such as acetate, propionate, and butyrate, which help support the gut environment and may influence wider body systems.
That matters because fatigue is not only about how many hours you sleep. It can also be linked to how well your body is nourished, how stable your energy feels, how your gut is functioning, and how much inflammatory or stress load your body is carrying.
Fibre is not a cure for fatigue. But it may be one of the simplest daily habits that supports the systems that fatigue often disrupts.
What does the research say about diet and chronic fatigue?
A systematic review by Campagnolo and colleagues examined dietary and nutrition interventions for chronic fatigue syndrome/myalgic encephalomyelitis, also known as CFS/ME. The review found that CFS/ME is characterised by persistent, unexplained fatigue lasting at least six months, often accompanied by symptoms such as unrefreshing sleep, post-exertional malaise, difficulty with memory or concentration, pain, and gastrointestinal symptoms.²
Importantly, the review did not find strong enough evidence to generally recommend nutritional supplements, elimination diets, or modified diets as a treatment for CFS/ME. Some interventions showed possible improvements in fatigue, including NADH, probiotics, high-cocoa polyphenol-rich chocolate, and NADH combined with coenzyme Q10, but the authors concluded that the overall evidence was limited by small sample sizes, short study durations, and inconsistent methods.²
This is an important point for consumers: when fatigue feels persistent, it can be tempting to chase a single “magic” supplement. But the current evidence suggests we should be careful with big claims made by these products.
Instead, the more reliable starting point is the boring-but-important foundation: a balanced, nourishing diet that supports the body consistently. This may include fibre-rich whole foods such as vegetables, fruit, legumes, nuts, seeds, and whole grains where tolerated, as well as functional foods designed to make key nutrients easier to include in everyday life.
And fibre is an essential part of that foundation.
Why fibre may matter when you feel constantly tired
A second systematic review by Jones and Probst looked at dietary modification for chronic fatigue syndrome symptoms. Again, the evidence was narrow and inconsistent, and the authors concluded that no definitive dietary modification could be recommended for symptom relief.³
However, one detail stood out: in one study discussed within the review, 95% of participants had poor fibre intake, alongside unhealthy fat, fruit, and vegetable intake patterns.³
That does not prove that low fibre causes fatigue. It also does not mean fibre is irrelevant. In science, a lack of strong evidence does not always mean something is untrue. Sometimes, it simply means that not enough high-quality research has been conducted yet to reach a confident conclusion, especially in a field that is still evolving.
What it does highlight is a common issue: when people are exhausted, diet quality often drops. They may eat fewer fruits, vegetables, legumes, and whole grains, which are also the major dietary sources of fibre.
This can then become a difficult feedback loop.
You feel tired, so you reach for quick energy.
Quick energy does not always support stable nutrition.
Lower-quality intake can affect gut comfort, mood, sleep, and overall wellbeing.
Then you feel even more tired.
Fibre helps shift the focus away from “quick fixes” and back toward nourishment. It may not be the whole answer, but it is one practical place to start while the science continues to grow.
Fibre, gut health, and the wider energy picture
Gut symptoms are commonly reported in people with chronic fatigue syndrome, including bloating, abdominal pain, altered bowel habits, food intolerance, and irritable bowel syndrome-like symptoms.²
This does not mean all fatigue starts in the gut. But it does suggest that the gut is part of the wider fatigue picture for many people.
Fibre supports the gut in several ways. It can help with bowel regularity, support stool formation, feed beneficial gut bacteria, and contribute to the production of short-chain fatty acids. These compounds are being studied for their role in gut barrier integrity, immune signalling, and inflammation.
Fatigue is not always physical either. Sometimes it feels like brain fog, low motivation, emotional heaviness, or being unable to concentrate.
The review by Campagnolo and colleagues noted that CFS/ME can involve cognitive symptoms and psychological wellbeing. Some nutrition-related interventions showed possible improvements in neurocognitive fatigue or anxiety, although the evidence remained limited and not strong enough for broad recommendations.²
A broader review on healthy eating, physical activity, and sleep hygiene, known as HEPAS, argues that healthy eating, movement, and sleep are deeply connected in supporting physical and mental health. It also highlights that diet can influence brain function through energy metabolism, synaptic plasticity, gut microbiota modulation, inflammation, and other pathways.⁴
This is where fibre becomes interesting.
Fibre-rich foods usually do not work alone. They come packaged with other helpful compounds: polyphenols, vitamins, minerals, antioxidants, and slowly digested carbohydrates. A high-fibre diet is often a marker of a more nutrient-dense dietary pattern.
So when we talk about fibre, we are not only talking about grams on a nutrition panel. We are talking about a way of eating that tends to better support the gut, metabolism, and brain.
Why “just rest” may not be enough
Rest is important. Sleep is important.
But if you are still tired after taking a break, it may be worth asking what your body is resting with.
Is it resting with enough nourishment?
Enough fibre?
Enough water?
Enough gentle movement?
Enough connection?
Enough regular sleep?
The Australian Government recommends a healthy diet that includes plenty of fruit and vegetables, grain and cereal-based foods, lean meats or plant-based alternatives such as tofu, nuts, seeds, and legumes, dairy or alternatives, and plenty of water.¹ Many of these foods are also natural sources of dietary fibre.
So, instead of thinking of fibre as an “extra,” it may be more useful to think of it as one of the signs that your diet is supporting your body properly.
A gentle way to start rebuilding energy
When you are exhausted, complicated routines can feel impossible, especially when they involve planning, shopping, cooking, and trying to include every food group perfectly.
That is why fibre can be a practical starting point.
You do not need to overhaul your whole life overnight. You can start by adding one small fibre-supporting habit each day.
That might look like:
Adding fruit to breakfast.
Choosing whole grains more often, if suitable for you.
Adding legumes to a meal.
Eating more vegetables across the day.
Drinking enough water.
Using a fibre-rich functional food that fits into your routine.
But we also understand that “just eat more fibre” is not always easy in real life.
You might be busy. You might have a sensitive gut. You might not tolerate certain high-fibre foods well. You might have dietary restrictions, such as gluten sensitivity or coeliac disease, that make common fibre sources harder to rely on.
That is the reason why we created PuriFibre: because we want to bring an effective, science-backed functional food, not a supplement, that is user-friendly in the real world and makes it easier to reach your daily fibre target.
We believe gut health should feel simple, not overwhelming. Fibre is not a cure for burnout, chronic fatigue, or medical fatigue. But it can be a gentle daily habit that helps support the foundation your body relies on.
Sometimes, the answer is to rebuild from the basics.
And fibre is one place to begin.
Important note
Persistent fatigue can have many causes, including iron deficiency, thyroid disorders, sleep problems, infection, chronic fatigue syndrome/myalgic encephalomyelitis, mental health conditions, medication effects, and other medical concerns. If your tiredness is ongoing, severe, unexplained, or not improving with rest and lifestyle support, please speak with a healthcare professional.
References
- Australian Government Department of Health, Disability and Ageing. The Domino Effect of Being Physically Active, Eating and Sleeping Well; 2024. https://www.health.gov.au/news/the-domino-effect-of-being-physically-active-eating-and-sleeping-well
- Campagnolo, N.; Johnston, S.; Collatz, A.; Staines, D.; Marshall-Gradisnik, S. Dietary and Nutrition Interventions for the Therapeutic Treatment of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: A Systematic Review. J. Hum. Nutr. Diet. 2017, 30, 247–259. https://doi.org/10.1111/jhn.12435
- Jones, K.; Probst, Y. Role of Dietary Modification in Alleviating Chronic Fatigue Syndrome Symptoms: A Systematic Review. Aust. N. Z. J. Public Health 2017, 41, 338–344. https://doi.org/10.1111/1753-6405.12670
- Briguglio, M.; Vitale, J. A.; Galentino, R.; Banfi, G.; Zanaboni Dina, C.; Bona, A.; Panzica, G.; Porta, M.; Dell’Osso, B.; Glick, I. D. Healthy Eating, Physical Activity, and Sleep Hygiene (HEPAS) as the Winning Triad for Sustaining Physical and Mental Health in Patients at Risk for or with Neuropsychiatric Disorders: Considerations for Clinical Practice. Neuropsychiatr. Dis. Treat. 2020, 16, 55–70. https://doi.org/10.2147/NDT.S229206
