The Fibre Crisis: Why most people dont get enough fibre and what its doing to their health

Fibre Crisis

In the world of wellness and nutrition, fibre often gets overshadowed by protein trends, superfood fads, and supplement stacks. Yet, behind the scenes, a silent health crisis is unfolding. A crisis that is reshaping gut health, metabolic resilience, and long-term disease risk.

Welcome to the Fibre Gap: a widespread deficiency in one of the most foundational nutrients in the human diet. It’s time to reframe fibre not as a digestive afterthought, but as a powerful driver of whole-body health.

Fibre: The Unsung Hero of Human Health

At its core, dietary fibre is the indigestible part of plant foods found in fruits, vegetables, legumes, whole grains, nuts, and seeds. Unlike other macronutrients absorbed in the small intestine, fibre travels to the colon, where it becomes fuel for the gut microbiome, a thriving ecosystem of bacteria that profoundly influences immunity, metabolism, inflammation, and even mood.

Fibre exists in two forms:

• Soluble fibre forms a gel-like substance that slows digestion, helping regulate blood sugar and cholesterol. Soluble fibers, such as β-glucan, psyllium, and pectin, are known for their ability to lower cholesterol and improve glycemic control due to their high viscosity (1, 2). They are also easily metabolized by gut microbiota, producing beneficial metabolites (3). 
• Insoluble fibre adds bulk to stool and promotes healthy bowel movements. Insoluble fibers, such as cellulose and lignin, primarily aid in digestive health by increasing fecal bulk and reducing intestinal transit time, which helps prevent constipation (1, 2).

Together, these fibres orchestrate a cascade of physiological benefits: from microbial diversity to immune defense. Fibre is far more than just a tool for regularity.

The Fibre Gap: A Modern Nutrition Shortfall

Despite its importance, most people in Western societies are consuming barely half the recommended daily intake. The World Health Organization advises 25–30 grams per day (4), yet many average just 15 grams or less.

This decline parallels the rise of ultra-processed foods that are low in fibre, high in additives, and stripped of natural complexity. White bread, sugary snacks, and convenience meals have displaced fibre-rich staples, creating an environment where the microbiome is undernourished and imbalanced.

In contrast, ancestral diets were rich in tubers, wild greens, seeds, and legumes and likely provided upwards of 80–100 grams of fibre daily, fostering diverse microbial ecosystems that modern diets now fail to sustain.

What Happens When Fibre Is Missing?

The effects of low fibre intake are far-reaching, with implications that extend beyond digestion.

1. Microbiome Disruption

Fibre acts as a prebiotic, feeding beneficial gut bacteria. In its absence, microbial diversity declines, and opportunistic strains may degrade the gut lining, contributing to intestinal permeability, inflammation, and immune dysregulation (5). Research links low microbial diversity with autoimmunity, metabolic syndrome, obesity, and depression (6).

2. Digestive Dysfunction

Without sufficient fibre, bowel movements become irregular. Constipation, bloating, and sluggish digestion are common. Over time, this can reduce gut motility and lead to a reliance on laxatives, further disturbing the natural rhythm of the gastrointestinal system (7).

3. Blood Sugar & Cholesterol Imbalances

Soluble fibre slows glucose absorption, reducing post-meal blood sugar spikes, which is a key mechanism in the prevention of type 2 diabetes. It also binds to cholesterol in the gut, lowering LDL levels and supporting cardiovascular health (8, 9).

4. Increased Risk of Chronic Disease

Large-scale epidemiological studies, including data from the EPIC trial and Harvard’s School of Public Health, consistently show that higher fibre intake reduces the risk of:

• Colorectal cancer (10)
• Heart disease (11)
• Type 2 diabetes (12)
• Obesity and premature death (13)

Rebuilding a Fibre-Rich Diet: Simple, Sustainable Shifts

The solution doesn’t lie in drastic overhauls, but in thoughtful additions. Here’s how you can begin:

• Add plants to every meal. Think oats, leafy greens, lentils, nuts, seeds, and colourful vegetables.
• Aim for diversity, not just grams. The more variety in plant foods, the broader the spectrum of microbes you support.
• Set a goal of 30+ plant types per week (14). Herbs, spices, legumes, fruits, whole grains, and prebiotic-rich foods like garlic, onions, and leeks all count.
• Start slow. Increase fibre gradually and pair it with ample water to avoid digestive discomfort.

Fibre as a Driver of Resilience and Longevity

Beyond digestion, fibre is emerging as a powerful tool in longevity science. Fibre influences inflammation pathways, supports metabolic control, and enhances microbial resilience (15). It is a nutrient that bridges gut health with systemic health, positioning itself at the heart of disease prevention and vitality.

In a world overwhelmed with nutrition noise, fibre offers a simple, evidence-based anchor – one that doesn’t require perfection, only presence.

Your Next Step Toward Better Health

If there’s one question to start asking at every meal, it’s this: “Where’s the fibre?”

Not because it’s trendy, but because it’s fundamental. The fibre crisis may be silent, but its impact is loud and clear. With small, consistent choices, we can begin to close this gap, one bite, one plant, one fibre-rich meal at a time.

References

1. Mcrorie, J., & McKeown, N., 2017. Understanding the Physics of Functional Fibers in the Gastrointestinal Tract: An Evidence-Based Approach to Resolving Enduring Misconceptions about Insoluble and Soluble Fiber.. Journal of the Academy of Nutrition and Dietetics, 117 2, pp. 251-264 . https://doi.org/10.1016/j.jand.2016.09.021.
2. Soliman, G., 2019. Dietary Fiber, Atherosclerosis, and Cardiovascular Disease. Nutrients, 11. https://doi.org/10.3390/nu11051155.
3. Guan, Z., Yu, E., & Feng, Q., 2021. Soluble Dietary Fiber, One of the Most Important Nutrients for the Gut Microbiota. Molecules, 26. https://doi.org/10.3390/molecules26226802.
4. WHO updates guidelines on fats and carbohydrates: https://www.who.int/news/item/17-07-2023-who-updates-guidelines-on-fats-and-carbohydrates 
5. Makki, K., Deehan, E., Walter, J., & Bäckhed, F., 2018. The Impact of Dietary Fiber on Gut Microbiota in Host Health and Disease.. Cell host & microbe, 23 6, pp. 705-715 . https://doi.org/10.1016/j.chom.2018.05.012.
6. Slyepchenko, A., Maes, M., Jacka, F., Köhler, C., Barichello, T., McIntyre, R., Berk, M., Grande, I., Foster, J., Vieta, E., & Carvalho, A., 2016. Gut Microbiota, Bacterial Translocation, and Interactions with Diet: Pathophysiological Links between Major Depressive Disorder and Non-Communicable Medical Comorbidities. Psychotherapy and Psychosomatics, 86, pp. 31 – 46. https://doi.org/10.1159/000448957.
7. Katsirma, Z., Dimidi, E., Rodriguez-Mateos, A., & Whelan, K., 2021. Fruits and their impact on the gut microbiota, gut motility and constipation.. Food & function. https://doi.org/10.1039/d1fo01125a.
8. Tamargo, A., Martín, D., Del Hierro, J., Moreno-Arribas, M., & Muñoz, L., 2020. Intake of soluble fibre from chia seed reduces bioaccessibility of lipids, cholesterol and glucose in the dynamic gastrointestinal model simgi®.. Food research international, 137, pp. 109364 . https://doi.org/10.1016/j.foodres.2020.109364.
9. Juhász, A., Greff, D., Teutsch, B., Gede, N., Hegyi, P., Horváth, E., Deák, P., Nyirády, P., Ács, N., & Juhász, R., 2022. Galactomannans are the most effective soluble dietary fibers in type 2 diabetes: a systematic review and network meta-analysis.. The American journal of clinical nutrition. https://doi.org/10.1016/j.ajcnut.2022.12.015.
10. Zhao, J., Zhu, Y., Du, M., Wang, Y., Vallis, J., Parfrey, P., McLaughlin, J., Qi, X., & Wang, P., 2022. Association between Dietary Fiber Intake and Mortality among Colorectal Cancer Survivors: Results from the Newfoundland Familial Colorectal Cancer Cohort Study and a Meta-Analysis of Prospective Studies. Cancers, 14. https://doi.org/10.3390/cancers14153801.
11. Alahmari, L., 2024. Dietary fiber influence on overall health, with an emphasis on CVD, diabetes, obesity, colon cancer, and inflammation. Frontiers in Nutrition, 11. https://doi.org/10.3389/fnut.2024.1510564.
12. Li, M., & , S., 2024. A review of healthy role of dietary fiber in modulating chronic diseases.. Food research international, 191, pp. 114682 . https://doi.org/10.1016/j.foodres.2024.114682.
13. O’keefe, S., 2019. The association between dietary fibre deficiency and high-income lifestyle-associated diseases: Burkitt’s hypothesis revisited.. The lancet. Gastroenterology & hepatology, 4 12, pp. 984-996 . https://doi.org/10.1016/s2468-1253(19)30257-2.
14. Why should you eat 30 plants a week? https://zoe.com/learn/30-plants-per-week 

Yu, X., Liang, X., Han, K., Shi, F., Meng, N., & Li, Q., 2022. Anti-Aging Effect of Dietary Fiber Compound Mediated by Guangxi Longevity Dietary Pattern on Natural Aging Mice. Nutrients, 14. https://doi.org/10.3390/nu14153181.