Fibre: effect, daily requirements and food

Fibre (also referred to as dietary fibre and plant fibre) is a constituent part of certain plant-based foods. It performs various tasks within the body – such as during digestion. for example. Fibre also influences the colour and shape of stools. The microbiome in the gut benefits from fibre too, as it increases the variety of good intestinal bacteria. Dietary fibres consist primarily of long-chain polysaccharides. These are a specific type of carbohydrates. Experts differentiate between soluble and insoluble fibres. 

Soluble fibre

Combined with water, soluble fibres (e.g. inulin, pectin and resistant starch) form a gelatinous substance. As a result, soluble fibre impacts the texture and size of our stool, making it softer and larger. This in turn facilitates regular emptying of the bowel. This makes fibre an effective remedy against constipation. It also provides nourishment for the intestinal bacteria. The bacteria in the large intestine break down this type of dietary fibre and multiply when you get enough of it. 

Insoluble fibre

Insoluble fibres (e.g. lignin and cellulose) bind water, which causes them to swell significantly. This increases the size of the stool – making it pass through the intestine faster. In doing so, insoluble fibres aid regular digestion. This type of dietary fibre is barely broken down by our intestinal bacteria. 

Fibre has an effect on our gut, and therefore our digestion. And it has a host of other favourable effects on the body too:

• Fibre reduces cholesterol in the body. It binds bile acid in the digestive tract. The body excretes this more quickly and forms it again. For this it needs cholesterol, reducing our cholesterol level.
• Fibre also influences blood pressure. Intestinal bacteria produce a specific fatty acid from dietary fibre called propionic acid. This stabilises blood pressure.
• Fibre also has a positive effect on blood sugar levels. It reduces the risk of type 2 diabetes.
• Fibre can also aid weight loss, because it helps keep you full for longer. 
• Plant fibre reduces the risk of cardiovascular diseases. That’s because it keeps you fuller for longer and, under certain circumstances, can help to reduce excess weight. It also lowers blood sugar and cholesterol levels. This has a positive effect on the cardiovascular system.
• Fibre promotes intestinal activity and helps us to excrete potentially harmful substances. This reduces the likelihood of developing colon cancer.

Daily fibre requirements vary depending on age. Roughly 30 grams per day are recommended for healthy adults, and a little less for children and adolescents. Opt for a balanced diet with plenty of fruit and vegetables as well as wholegrain products to ensure you take on board sufficient dietary fibres. For instance, five portions of fruit and vegetables, one portion of wholegrains (e.g. wholemeal pasta, quinoa, brown rice), three slices of wholemeal bread and two to three medium-sized potatoes are adequate.

Note that women should ideally get 30 grams of fibre a day while pregnant and breastfeeding. 

Fibre-rich foods are part of a balanced diet. But which foods are high in fibre? Dietary fibres are contained almost exclusively in plant-based foods – primarily in fruit and vegetables, wholegrains, pulses and nuts. Animal-based food products, on the other hand, contain almost zero fibre. 

Foods which are particularly high in fibre include:

• Fruit, especially avocados, apples, pears, plums and apricots
• Berries such as blackberries and raspberries
• Vegetables such as sprouts, kale, broccoli, artichoke, celeriac and sweet potatoes
• Wholegrains, including oats, quinoa, couscous and brown rice, as well as products made from wholegrain (e.g. oat flakes, bread and pasta)
• Pulses like beans, chickpeas, lentils
• Nuts, kernels and seeds, like flaxseeds, chia seeds, sunflower and pumpkin seeds, almonds, walnuts and pistachios
• Bran and psyllium husks

Note that there are many more foods that contain fibre. This is not an exhaustive list. The table below gives you a few ideas about how you can meet your daily dietary fibre requirements (quantities per person):

These tips can help you on your way towards a diet with lots of high-fibre foods:

• Plan meals in advance and shop accordingly. This will allow you to ensure that you have all the food you need in the house.
• Swap sweets for fruit and vegetables. This will help you boost your dietary fibre intake.
• Always opt for the wholemeal version of bread, pasta, rice, etc.
• Avoid processed foods. Opt instead for natural and fresh foods if you want to eat more fibre.
• Want to eat more fibre? Increase your intake gradually. Drink enough water too, ideally around 2.5 litres per day. This will allow the fibre to take optimal effect.
  

Dietary fibres can enrich your diet in a variety of ways. For instance, they aid digestion and stabilise blood glucose levels. Getting enough fibre also boosts your fitness and well-being. Consciously incorporate fibre-rich foods into your daily routine so you can benefit from its positive effects in the long term.