How GPs can champion dietary fibre
Most Australians are not meeting their daily recommended fibre intake, with only 28% of adults consuming an adequate amount of fibre each day.1 This is a concerning statistic, as fibre is an essential nutrient and crucial to many aspects of our health.
What is fibre?
Dietary fibre is a nutrient that can be derived from the indigestible part of plant foods such as vegetables, fruits, grains, nuts, seeds and legumes. There are two main types of fibre, soluble and insoluble, which have different health benefits and functions.
Soluble fibre absorbs water to form a gel during digestion, which increases food transit time, delays gastric emptying and slows the digestive process. This may help promote post-meal satiety. Soluble fibre has also been shown to improve lipid profiles and blood sugar levels.2
Insoluble fibre, found in the outer skins and surfaces of grains, seeds and roots, decreases food transit time and increases faecal bulk, supporting regular bowel movements and promoting a feeling of fullness. Insoluble fibre also helps to eliminate waste from the body, targeting potentially harmful molecules for removal.3
Why is it so important?
Optimising dietary fibre intake is an important component of any relevant dietary management plan.
For example, increasing daily fibre intake by 15 g or to 35 g may be a reasonable target that would assist with medical management.4
While fibre is beneficial for many things, its main benefit is to maintain good digestive health, meaning appropriate nutrient absorption, intestinal motility, immune function and a balanced gut microbiota. Good digestive health is associated with fewer digestive symptoms such as bloating, constipation, and abdominal pain or discomfort.2
A low fibre diet is one of many risk factors for digestive issues such as irritable bowel syndrome (IBS), possibly due to effects on microbial diversity and gut permeability, and careful tailoring of fibre intake is an important part of management.5
How GPs can champion fibre
See below for some of my simple tips on how GPs can champion the benefits of fibre when talking to patients:
1. Stress the convenience
Stress how convenient it can be to incorporate fibre into the diet. Fibre is found in a wide and varied range of foods, so suggest some simple and convenient ways to meet their recommended daily intake.
This can be as simple as:
- adding an extra half a cup of vegetables to every dinner
- switching to wholemeal bread or brown rice (2 slices of wholemeal bread contain about 5g of fibre in comparison to white bread which only has 2g)
- choosing high-fibre breakfast cereals
- adding chopped fruit or a teaspoon of psyllium husk to breakfast cereal
- having fresh fruit for dessert.
2. Promote high-fibre foods
While fibre is present in many foods, it is important to highlight the key food groups: fruits, vegetables, beans/legumes, whole grain foods and high fibre cereal. The fibre content of some common foods is shown in the table below.6
Note that fruits, vegetables, oats, barley and legumes are particularly high in soluble fibre, while insoluble fibre is found in higher amounts in wholegrain breads and cereals, nuts, seeds, wheat bran and the skin of fruit and vegetables.
Source: Fibre, Nutrition Australia.6
Below is an example of how an adult could meet their daily dietary fibre requirements:
- 1 cup of bran-based breakfast cereal (such as All-Bran flakes)* = 7.7g
- 2 slices of wholegrain bread = 4.8g
- 1 apple and a banana = 4.5g
- Handful of almonds = 2.6g
- 1 cup of carrots = 6.9g
- 1cup brown rice = 2.7g
- 1 cup popcorn = 1.2g
3. Advise on recommended intake
As most individuals are currently not consuming enough fibre, it is important to advise and make patients aware of their recommended daily intake of 25g for adult women and 30g for adult men.1 On average, according to the last national nutrition survey, Australians are consuming about 22g of fibre per day.7 Advise patients that achieving the recommended intake can be done without needing to add many more kilojoules.
4. Suggest alternatives
When promoting high-fibre foods it is important to consider alternative diets and food intolerances, so have alternative sources and suggestions available.
Gluten free grains (such as corn, millet, rice, quinoa) are generally lower in fibre than wheat, barley and other gluten-containing grains.
Some gluten-free cereal options are available with a higher fibre content, such as Sultana Bran Gluten Free which is made with rice bran and chickpea flour.^ Plenty of gluten-free breads are also available, including seeded and wholemeal varieties, and people should be encouraged to read the label and compare fibre content for different products.
Legumes in general, such as chickpeas and pulses such as lentils, are gluten-free and have a very high fibre content.
5. Drink fluids
As dietary fibre tends to absorb fluids, individuals must continue to drink sufficient liquids, including water, when consuming more fibre. Increasing fibre intake without increasing fluid intake can lead to abdominal discomfort, so it is important to stay hydrated.
* A 40 g (1 cup) serve of All-Bran Flakes contains 7.7g g of dietary fibre (26% of the recommended daily intake, based on an average adult diet of 8700 kJ).
^ A 45 g serve of Sultana Bran Gluten Free contains 4.6 g of dietary fibre (15% of recommended daily intake, based on an average adult diet of 8700 kJ).
- Fayet-Moore, et.al, 2018, Dietary Fibre Intake In Australia, Nutrients,10: 599.
- Dahl WJ, Stewart ML. Position of the Academy of Nutrition and Dietetics: Health Implications of Dietary Fiber. Journal of the Academy of Nutrition and Dietetics. 2015;115(11):1861-70.
- Soliman GA. Dietary fiber, atherosclerosis, and cardiovascular disease. Nutrients 2019; 11(5): 1155.
- Reynolds AN, Akerman AP, Mann J. Dietary fibre and whole grains in diabetes management: Systematic review and meta-analyses. PLoS Med. 2020 Mar 6;17(3):e1003053.
- Yan R, Andrew L, Marlow E, et al. Dietary Fibre Intervention for Gut Microbiota, Sleep, and Mental Health in Adults with Irritable Bowel Syndrome: A Scoping Review. Nutrients. 2021;13(7):2159.
- Nutrition Australia. Fibre. Produced October 2014, Revised: July 2021. Available at: www.nutritionaustralia.org/fact-sheets/fibre-2/ Accessed November 2021.
- Australian Bureau of Statistics. Australian Health Survey 2011-12.
Sam Hay is a practicing Australian GP who is passionate in engaging the community through a wide range of media roles, including being the medical expert on the show “SAS”, regular appearances on breakfast shows and radio programs, as well as writing for the parenting website Kidspot.
A former Senior Medical Officer in the Royal Australian Army Medical Corps, Dr Hay has been working in general practice since 2005 and is currently a partner in a prominent Sydney-based general practice network. Dr Hay started his military career at the 1st Health Support Battalion with the Parachute Surgical Team, facing his greatest challenges in Afghanistan where he led a small medical team retrieving and evacuating injured soldiers from the combat zone working with an American helicopter-based retrieval team.
Dr Sam is a self-confessed health and fitness advocate who can be found in the gym or the surf.
Dr Sam Hay – BMedSci, MBBS(Hons), FRACGP, Graduate Diploma of Sports Medicine, Diploma of Child Health
This blog is sponsored by Kellogg's.