Fibre is basically the indigestible portion of plants, be that vegetables, fruits, grains, legumes, nuts or seeds. Although we human beings can’t digest fibre, it is a really important dietary component for us for a number of reasons. So what is it, how much do we actually need and where do we find it?
Fibre is a complex carbohydrate. It’s divided into two basic categories, soluble and insoluble which can then be further broken down into the different types including inulin, lignin, beta glucans, resistant starch etc. That said, fibre-rich foods usually contain both soluble and insoluble forms. The health-boosting benefits of fibre include promoting digestive health, helping with blood sugar control and cholesterol management.
It is, as the name implies, soluble in water and actually absorbs liquids to form a gel-like substance. This gel-like quality is what enables soluble fibre to help lubricate the bowels and to bind to things like excess cholesterol. It also acts as a prebiotic - food for probiotics or our gut bacteria - and can help to lower a food’s glycaemic load which in turn helps to control our blood sugar levels.
Sources: carrots, artichokes, almonds, chia seeds, linseeds (flax seeds), figs, oats, barley, bananas, potatoes, onions, avocado, plums and garlic
This isn’t soluble in water, surprise! It does however, add texture and bulk to food which helps us to feel full but also, together with soluble fibre, aids digestion. Insoluble fibre tends to have a rougher texture which adds volume to our stools which helps their movement through our bowels.
Sources: wholegrains, legumes, most fruits and vegetables (particularly in the skins), nuts, seeds
How Much Do We Need?
The recommended amount of fibre per day is 21-38g. However, rather than weighing your food, a great way you can be intentional about increasing the amount of fibre you're getting is to up the amount of plants you eat - fruit, veg, nuts, seeds, legumes and wholegrains. A few simple ideas for doing this are:
Add an extra portion of veggies to your main meals
Use half the amount of meat you usually would in meat dishes and replace the other half with beans (or go full beans if you're up for it!)
Add fruit nuts and seeds to snacks or on top of cereal or porridge
Swap white for wholegrain, or half anf half
Eat the skins on your potatoes
When we add more fibre to our diets it's usually a good idea to do so gradually so as to minimise any gastrointestinal upset and to increase the amount of water we drink too. Remember that you can listen to your body here. How does eating certain foods make you feel? How is your digestion? You know your body best!
Buttriss, J. L. and Stokes, C. S. (2008), Dietary fibre and health: an overview. Nutrition Bulletin, 33: 186-200. doi:10.1111/j.1467-3010.2008.00705.x
British Nutrition Foundation, Dietary Fibre, https://www.nutrition.org.uk/healthyliving/basics/fibre.html
Precision Nutrition's Encyclopedia of Food, Fibre, https://www.precisionnutrition.com/encyclopedia/food/fiber