Fibre: Why it's great it's back in focus

Fibre is increasingly becoming a central focus among the public, as well as nutrition research. While fibre has long been associated with bowel regularity, emerging evidence continues to reinforce its broader role in cardiometabolic health, glycaemic control, weight regulation, and long-term disease prevention.

The fibre gap

Despite this, most Australian adults are not meeting recommended intake levels of 25 g/day for women and 30 g/day for men, according to the National Health and Medical Research Council Nutrient Reference Values [1].

National data consistently show intakes well below these targets. National survey data show median adult intake ~20.7 g/day and that <20% of adults reach the Suggested Dietary Target for chronic disease reduction [1].

What the research shows

High dietary fibre intake is strongly associated with reduced risk of:

• Cardiovascular disease [2]

• Type 2 diabetes [2]

• Colorectal cancer [2]

• All-cause mortality [2]

A Lancet series of 185 cohorts and 58 trials reported 15–30% lower all‑cause and cardiovascular mortality, CHD, stroke, T2D and colorectal cancer when comparing highest vs lowest fibre intakes, with greatest risk reduction around 25–29 g/day and further benefit at higher intakes [2].

Additionally, a recent umbrella review found highly suggestive evidence linking higher fibre to lower CVD mortality, diverticular disease, several cancers and all‑cause mortality [3].

In clinical practice, fibre is a low-cost, low-risk intervention with measurable benefits.

Matching fibre to the patient

Not all fibre behaves the same physiologically. Tailoring advice can improve outcomes:

Type 2 diabetes / insulin resistance

Soluble, viscous fibres (e.g. oats, legumes, barley, psyllium) slow gastric emptying and carbohydrate absorption, reducing postprandial glucose excursions and modestly lowering HbA1c [4].

Hyperlipidaemia

Beta-glucan (oats, barley) and psyllium supplementation have demonstrated LDL-lowering effects through increased bile acid excretion [5].

Overweight and obesity

Higher fibre diets improve satiety and reduce overall energy intake without deliberate restriction [4].

Constipation

Insoluble fibres increase stool bulk and reduce transit time, provided fluid intake is adequate [5].

Irritable bowel syndrome

Soluble fibres are generally better tolerated than coarse insoluble sources. Gradual introduction is essential to minimise bloating [6].

Why it matters for GPs

Patients with the lowest fibre intakes are often those at highest chronic disease risk: individuals consuming high amounts of refined carbohydrates, ultra-processed foods, and minimal plant variety.

Even small shifts, such as swapping white bread for wholegrain, adding legumes to meals, choosing oats at breakfast, can help increase intake. Gradual increases (5g increments) alongside adequate hydration help improve tolerance and reduce gastrointestinal discomfort.

Fibre is under‑consumed, low cost, and a high‑impact public‑health and clinical target [7].

Fibre remains one of the most under-consumed yet clinically impactful nutrients. It requires no prescription, carries minimal risk, and addresses multiple chronic disease pathways simultaneously. Encouraigng adequate fibre intake may be one of the simplest interventions available in general practice.

Referral to an Accredited Practising Dietitian can further support individualised implementation, particularly for patients with metabolic disease, IBS, or complex dietary needs.

– Sarah Marko, Accredited Practising Dietitian

Next steps in your learning journey

🎓 Certificate Courses in Clinical Nutrition
Dive deeper with our university-assured, structured Professional Diploma pathway. ➡️ Explore Certificate Program >

🎓 Short Courses in Clinical Nutrition
Explore single-topic CPD courses in focused areas of clinical nutrition. Complete in less than 10 hours, from $195. ➡️ Browse Clinical Nutrition short courses >

🎓 HealthCert 365 
Prefer flexible learning across many topics? Access 4,000+ CPD hours on-demand with HealthCert 365 — anytime, any topic, one flat annual fee.
➡️ Discover HealthCert 365 >

Explore more educational content in Clinical Nutrition

CPD self-submission

You can self-record CPD for this blog. Quick Log CPD hours with the RACGP/ACRRM via the usual self-submission process. You will be asked to reflect on what you have learned, and you will require supporting evidence such as a screenshot. For more information, view the: RACGP CPD guide | ACRRM CPD guide

References

1. Fayet-Moore, F., Cassettari, T., Tuck, K., McConnell, A., & Petocz, P. (2018). Dietary Fibre Intake in Australia. Paper I: Associations with Demographic, Socio-Economic, and Anthropometric Factors. Nutrients, 10. https://doi.org/10.3390/nu10050599.
2. Reynolds, A., Mann, J., Cummings, J., Winter, N., Mete, E., & Morenga, L. (2019). Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. The Lancet, 393, 434-445. https://doi.org/10.1016/s0140-6736(18)31809-9.
3. Veronese, N., Gianfredi, V., Solmi, M., Barbagallo, M., Dominguez, L., Mandalà, C., Di Palermo, C., Carruba, L., Solimando, L., Stubbs, B., Castagna, A., Maggi, S., Zanetti, M., Al-Daghri, N., Sabico, S., Nucci, D., Gosling, C., & Fontana, L. (2025). The impact of dietary fiber consumption on human health: An umbrella review of evidence from 17,155,277 individuals.. Clinical nutrition, 51, 325-333 . https://doi.org/10.1016/j.clnu.2025.06.021.
4. Reynolds, A., Akerman, A., & Mann, J. (2020). Dietary fibre and whole grains in diabetes management: Systematic review and meta-analyses. PLoS Medicine, 17. https://doi.org/10.1371/journal.pmed.1003053.
5. McKeown, N., Fahey, G., Slavin, J., & Van Der Kamp, J. (2022). Fibre intake for optimal health: how can healthcare professionals support people to reach dietary recommendations?. The BMJ, 378. https://doi.org/10.1136/bmj-2020-054370.
6. Cronin, P., Joyce, S., O’Toole, P., & O'Connor, E. (2021). Dietary Fibre Modulates the Gut Microbiota. Nutrients, 13. https://doi.org/10.3390/nu13051655.
7. Barber, T., Kabisch, S., Pfeiffer, A., & Weickert, M. (2020). The Health Benefits of Dietary Fibre. Nutrients, 12. https://doi.org/10.3390/nu12103209.