Are you eating enough fibre?
Fibre isn't just for digestion, it can help keep your heart healthy too. But most of us don't eat enough fibre. Senior Dietitian Victoria Taylor explains what fibre is, why we need it, and how to get more fibre into your diet.
What is fibre?
Dietary fibre, which you might know as roughage (the old term for it), is the name for substances in plant foods that cannot be completely broken down by digestion. It’s only found in foods that come from plants, and specifically in starchy carbohydrates, fruit, vegetables, beans and lentils.
Higher intakes of dietary fibre are associated with a lower risk of heart and circulatory disease, type 2 diabetes and some cancers.
Animal products such as meat, fish, eggs and dairy products, like cheese and yoghurt, don’t contain any fibre. Nor do fats, whether they are plant or animal-based.
Why is fibre good for us?
We’ve known for a long time that fibre helps keep our digestive system healthy. However, in the past 25 years research in this field has moved on and we’ve discovered other benefits. Higher intakes of dietary fibre, especially from cereal fibre and wholegrains, are associated with a lower risk of heart and circulatory disease, type 2 diabetes and some cancers.
As a result, the official recommendation on the amount of fibre we should be eating has been increased. The recommendation comes from a 2015 report on carbohydrates and health by the Scientific Committee on Nutrition, which advises government bodies.
How much fibre should I be eating?
The current recommendation is that adults should eat 30g of fibre a day. Currently, average intakes are around 20g a day, so most of us have a long way to go. To reach 30g, make sure that as well as choosing higher-fibre options at meals, your snacks are rich in fibre too.
To help the fibre do its job, make sure you are drinking enough fluid, especially if it’s hot or you’re being physically active
The good news is that most sources of fibre fit well into a healthy, balanced diet that will help to protect you from heart and circulatory disease. Fruit, vegetables, wholegrains, beans, pulses, nuts and seeds are the foods to look out for. If you are buying ready-made products like bread, pasta or ready meals, check the nutritional information on the back of the pack. It needs to contain 3g per 100g to be called a source of fibre and 6g per 100g (or 3g per 100kcals) to claim to be high in fibre.
Won’t eating more fibre give me wind?
Some people are put off eating more fibre because they think it might affect their digestion. Bloating and flatulence can be associated with a sudden increase in the amount of fibre in your diet. To avoid this, increase the amount of fibre you are eating gradually. Make one change at a time, introducing the next once your body has adjusted. To help the fibre do its job, make sure you are drinking enough fluid, especially if it’s hot or you’re being physically active.
Are all types of fibre the same?
There are different types of fibre, which have different effects on our bodies and health, so it’s important to include them all in your diet.
Insoluble fibre is probably what you think of as fibre. It helps us to have a healthy digestive system by passing through our bodies without being broken down. This helps other foods move through too, reducing the amount of time that takes. High-fibre breakfast cereals, wholegrains, vegetables, potatoes with skins, nuts and seeds are the kinds of foods that will provide us with insoluble fibre.
The main thing is to get plenty of fibre in a variety of wholegrains, beans, pulses, fruits and vegetables, as this will help you get the benefits of each fibre variety
Soluble fibre works differently, as it dissolves in water and forms a gel in the gut. This type of fibre helps to keep stools soft, which may help prevent or treat constipation. It may also help to lower cholesterol levels. It’s found in grains like oats, barley and rye, fruit, beans, pulses and vegetables such as carrots and potatoes.
Resistant starch is now also included in the definition of dietary fibre. It is found in foods such as bananas, potatoes, grains and beans. It can form in some starchy foods such as rice and potatoes when they are cooked and then cooled, and is also added to certain foods. It can’t be digested in the small intestine, but it does ferment in the large intestine. That may sound bad, but it’s actually helpful as it produces short-chain fatty acids, which helps keep the gut healthy.
There aren’t specific recommendations on the amounts of each type of fibre you should eat. The main thing is to get plenty of fibre in a variety of wholegrains, beans, pulses, fruits and vegetables, as this will help you get the benefits of each fibre variety. This also fits with the 5-a-day recommendations that we eat a range of different fruit and vegetables.
This sounds like hard work – can I just take a fibre supplement?
Fibre supplements are available from pharmacies and health food shops as tablets, in sachets to mix into a drink, or as a powder to add to food. Natural bran is
also used to add fibre to your diet. However, it’s better to get the fibre you need from whole foods. Adding raw bran to food can reduce the absorption of some minerals, such as iron and calcium, and a sudden increase in fibre could lead to bloating or wind.
Fibre supplements may also affect how some medicines work, so if your doctor or dietitian hasn’t recommended you take them, check with your doctor before you use them.
The benefits of oats
Products that contain oat beta glucans, a type of soluble fibre, are allowed to claim that they can help lower cholesterol levels if they contain at least 1g of beta glucans per serving. But remember, you need to consume at least 3g per day to actually get the cholesterollowering benefits.
However, don’t feel you have to buy products where oat beta glucans have been added. Oat-based products such as porridge, muesli, oatcakes, oat bread and some oat milks also contain oat beta glucans and are often cheaper.
If you have a variety of these foods across the day, you can get your 3g of oat beta glucans.