Dietary fibre is a large and varied group of indigestible carbohydrates that are found in plant foods (e.g. fruit, vegetables, wholegrains, legumes, nuts, seeds). As the name suggests, these carbohydrates escape digestion in the small intestine and therefore provide our bodies with much less kilojoules than digestible carbohydrates. In the large intestine (where the magic happens!) they are then partially or completely broken (fermented) into short chain fatty acids (especially butyrate), associated with a plethora of help benefits. These benefits include allowing the good bacteria to flourish while creating an unfavourable environment for harmful pathogens, enhancing our immune system, being anti-inflammatory, as well as promoting satiety (the feeling of fullness after a meal) which assists weight management. No wonder adequate dietary fibre intake is key to both gut health and associated with the reduced risk of so many diseases (including diabetes, heart disease, liver disease and several cancers).
Dietary fibre can be broadly labelled as soluble or insoluble, then just to confuse things a little more there is also resistant starch (which technically is an insoluble fibre but acts like a soluble fibre!). The most important thing to remember, each type plays a really important role in the body. For example:
Soluble fibre forms a thick gel like substance when in contact with water, slowing down digestion. This is beneficial for our heart, as it can assist in lowering LDL blood cholesterol by binding with bile acids and increasing their extraction. Soluble fibre also slows down the absorption of sugars, helping to stabilise our blood sugar levels. In the colon, soluble fibres are highly fermentable and have a prebiotic effect, encouraging the production of good bacteria and promoting a healthy bowel. Good sources of soluble fibre include: legumes, oats, barley, psyllium, pectin rich fruit (such as apples, pears), prunes, mango and most veg but especially green peas, brussels sprouts, green beans and onions.
On the other hand, insoluble fibre is non-water soluble, and therefore passes through the digestive tract intact. This adds bulk in the large intestine and assists food to travel through more quickly. Insoluble fibre helps keep us ‘regular’ and benefits overall digestive health by promoting removal of waste and reduces the risk of colon cancer. Great sources of insoluble fibre include wheat bran, wholegrains, brown rice, nuts, legumes (such as chickpeas, lentils) and the skins of fruit and vegetables.
The hero of gut health! Although essentially an insoluble fibre, resistant starch passes through the small intestine intact and is preferentially fermented by our gut bacteria and promotes that wonderful butyrate production (which we know is associated with lots of different benefits!). Good sources of resistant starch include legumes and wholegrains, as well as starches that have been cooked and then cooled (like cold potatoes or pasta in salads).
How much do we actually need?
The recommended total daily fibre intake for women is 25g, (or 30g for men). For the prevention of chronic disease, it is suggested we up this a little more to 28g/day for women (or 38g for men).
BUT it’s also about diversity!
It is not just the total amount that is important, it is the diversity. Given each type of fibre has something pretty special to offer, to really gain the most benefit it’s important we are consuming a variety of different soluble, insoluble and resistant starch rich foods.
Putting this all together
So, we know we should be eating adequate fibre, and we need diversity, but how do we achieve it. The easiest way is to eat an abundance of different plant foods. In fact, for optimal gut health, they say we should aim for 30 different plant food per day!
Try these easy fibre boosting tips
- Choose wholegrains (such as oats, brown rice, quinoa, spelt, wholemeal pasta, wholemeal bread) over skip highly refined white versions (white bread, pasta, rice) which have had most of the fibre removed.
- Eat more veg. Aim to include AT LEAST 6 different veg per day (remember diversity is key here).
- Keep the skin on fruit and veg when possible (the skin is fibre packed).
- Snack on berries such as strawberries and raspberries (all those tiny seeds are loaded with fibre).
- Legumes (such as chickpeas, lentils, black beans) are true fibre warriors. Aim to include at least 3-4 times per week. PLUS, legumes are also a great way to keep the overall cost of meals down being budget friendly too!
- Sprinkle porridge, salads and yoghurt with seeds or chopped nuts or add some chia seeds or psyllium to smoothie bowls to thicken and fibre enrich.
Smoothie bowl with frozen banana, spinach, chia seeds, nut butter, oats and milk of choice.
Wholegrain crackers topped with hummus and sliced tomato and cucumber
Greek yoghurt and berries
Brown rice, rocket & roasted veg salad
Grilled salmon with roasted sweet potato wedges (skin on), steamed broccoli, and sugar snaps
Article formulated for HUSTL. HEALTH.
Created by ®Chrissy Freer