It is easy to forget the importance of dietary fibre when you are inundated with information about important vitamins and minerals, or the latest ‘superfood’ on the market. And whilst quinoa porridge with nuts and fruit is not a very exciting subject (unless you’re a naturopath), dietary fibre is certainly vital to your ongoing good health.
What is fibre?
Fibre is part of the food which can’t be broken down and absorbed by your intestine. It is found in fruit, vegetables, nuts, seeds and legumes as well as grains (especially the outer covering which is often lost in highly processed foods).
Fibre keeps your digestive tract clean (it’s like a big broom for your gut) as well as encourages good elimination of waste and toxins through your bowels.
A diet low in fibre can increase your risk of bowel cancer, diverticulitis, constipation, gastrointestinal problems, increased cholesterol, heart disease, weight gain and more.
What are the different types of fibre?
Fibre is often classified into three different types; soluble, insoluble and resistant starch. It is worth noting that many foods contain a combination of soluble and insoluble fibre and therefore eating a varied diet which includes wholegrains, fruits and vegetables should provide you enough of the right types of fibre to maintain healthy bowel function.
Soluble fibre slows down the emptying process of your digestive system, therefore increasing the time it takes for your food to pass through. It is soluble in water (hence the name) and as a result attracts water and swells in the digestive tract ensuring your bowel movements are soft, formed and easy to pass.
Soluble fibre has the benefit of helping you feel fuller for longer and maintains blood sugar levels. You can find soluble fibre in all fruit and some vegetables (such as carrots, onion and broccoli), as well as oats, nuts and legumes.
Insoluble fibre does not dissolve in water and adds bulk or ‘roughage’ (as you may sometimes hear) to your bowel movements. It passes through your digestive system relatively unchanged and may reduce the incidence of constipation and haemorrhoids.
You can find insoluble fibre primarily in wholegrain products, however it can also be found in some vegetables, nuts, seeds and some fruit.
Resistant starch is not digested or not easily digested by your digestive enzymes (or at least less so than soluble and insoluble fibre). Consequently it travels to the large intestine where it feeds the good bowel flora (bacteria in the bowel) and thereby supports the healthy functioning of the bowel.
It is thought to have significant health benefits such as reducing inflammation in the bowel and therefore may reduce your risk of developing bowel cancer or other inflammatory conditions.
Similar to soluble fibre, resistant starch helps you feel fuller for longer and therefore is useful in healthy weight management and maintaining steady blood glucose levels.
You can find resistant starch in the many high fibre foods already listed, however the content will vary depending on the processing of these foods. For example, resistant starch is high in slightly green bananas and uncooked rolled oats as well as boiled potatoes, brown rice and legumes that are eaten cold.
How much fibre do you need?
It is generally recommended we aim for a minimum of 30 grams of fibre every day, however this may vary depending on your specific health needs. It also needs to come from a variety of sources (due to the different types of fibre) and not just from taking a fibre supplement or adding heaps of wheatbran to your cereal.
Many of us don’t achieve this guideline with women tending to consume less fibre on average than men (according to the Australian Institute of Health and Welfare).
Consuming large amounts of excess fibre (usually by way of a supplement) over a long period of time can lead to reduced absorption of certain minerals such as zinc, iron and calcium. So it really is best to make gradual dietary changes over time rather than use a fibre supplement. Food is the best way to go (when possible), not just for your bowels but for all aspects of your health too!
How can you get more fibre in your diet?
You can increase your fibre intake by making a few simple changes to your diet, such as swapping white breads, rice and pasta for wholemeal varieties and keeping the skin on your fruits and vegetables.
An example of a high fibre daily menu:
Breakfast – Untoasted muesli, topped with a chopped banana and blueberries
Snack – Carrot sticks with hummus dip and one apple
Lunch – Cooled brown rice and lentil salad with spinach, avocado, tomato, cucumber, parsley, and red onion
Snack – 1 slice of wholemeal bread topped with a nut butter spread (such as almond or cashew)
Dinner – Poached chicken with a jacket potato, broccoli and brussel sprouts
Dessert – Stewed pears (without the added sugar) and coconut/dairy yoghurt