Healthy Dietary Fiber
Dietary fiber is a word that is used for plant-based carbohydrates, unlike other carbohydrates (such as sugars and starch), that can not be digested in the small intestine and so enters the large intestine or colon.
Soluble and insoluble fibre
For instance, you may have come across the terms ‘soluble fiber’ or ‘insoluble fiber’. However, these are words that are used to describe the types of fiber in our diet.
Although scientific organizations dispute that these terms are no longer actually relevant, you may see these terms being used, with soluble fiber including pectins and beta-glucans (found for instance in foods like fruit and oats) and insoluble fiber including cellulose (found for instance in whole grains and nuts).
Although what is essential to remember is that fiber-rich foods typically include both types of fiber.
Fiber-rich foods include:
- Wholegrain breakfast cereals, wholegrain bread, wholewheat pasta and oats, barley and rye
- Fruit such as berries, melon, pears, and oranges
- Vegetables such as broccoli, carrots, and sweetcorn
- Peas, beans, and pulses
- Nuts and seeds
- Potatoes with skin
How Can Fiber Benefit your Health?
Firstly, fiber aids to keep your digestive system healthy and aids to prevent constipation. For instance, it bulks up stools, makes stools softer and easier to pass, and makes waste move through the digestive tract more instantly.
The European Food Safety Authority suggests that including fiber-rich foods in a healthy balanced diet can promote weight maintenance. Dietary fiber can reduce your risk of:
- Cardiovascular disease (heart disease and stroke) and type 2 diabetes: Uniquely, foods such as oats and barley contain beta-glucan, which may help to decrease cholesterol levels if you eat 3g or more of it daily, as part of a healthy diet.
- Colorectal cancer (bowel cancer): In fact, did you know that the World Cancer Research Fund (WCRF) estimates that 45% of bowel cancer could be prevented through diet, physical activity, and weight?
Fiber and Bowel Cancer
You equally agree that dietary fiber may help to protect against bowel cancer.
Although the reasons for this are not completely known, this may be because fiber additions stool size, dilutes content, and moves it faster through the gut so the amount of time waste products stay in contact with the bowel is reduced.
Additionally, some types of fiber may also improve gut bacteria produce helpful chemicals that can have useful effects on the bowel (see below).
Fiber and Good Bacteria
Recently, research has increasingly revealed how powerful the bacteria in our gut may be to our health, and it has been recommended that a fiber-rich diet can help improve the good bacteria in the gut.
However, some fiber types provide a food source for ‘friendly’ gut bacteria assisting them to increase and produce substances which are thought to be protective such as short-chain fatty acids.
How much Fiber do You Need?
In 2015 the government published new guidelines with a suggestion that the population’s fiber intake should rise to 30g a day for adults (aged 17 years and over).
On normal, we consume much less than this – about 18g per day. Children also need to increase their intake of fiber.
The recommended intake of fiber
|2-5||15g per day|
|5-11||20g per day|
|11-16||25g per day|
|17 and over||30g per day|
To enhance your fiber intake you could:
- Go for wholemeal or seeded whole grain bread. If your family only typically likes white bread, why not try the new recipes that combine white and wholemeal flours.
- Choose a high fiber breakfast cereal, for example, wholegrain cereal like wholewheat biscuit cereal, no added sugar muesli, bran flakes, or porridge. Why not add some fresh fruit, dried fruit, seeds, and/or nuts.
- Choose whole grains like wholewheat pasta, bulgur wheat, or brown rice.
- Go for potatoes with skins e.g. baked potato, wedges, or boiled new potatoes – you can eat these hot or use them for a salad.
- For snacks try fruit, vegetable sticks, oatcakes, rye crackers, unsalted nuts, or seeds.
- Moreso, include plenty of vegetables with meals – either as a side dish/salad or added to sauces, stews, or curries – this is a good way of getting children to eat more veg.
- Keep a supply of frozen vegetables so you are never without.
- Have some fresh or fruit canned in natural juice for dessert or a snack.
- Add pulses like beans, curries, lentils, or chickpeas to stews, and salads.
However, if you need to improve your fiber intake, it is a good idea to such regularly. It is likewise necessary to drink plenty of fluids (around 6-8 glasses per day for adults) and to try to be active for at least 150 minutes per week. See How much physical activity do I need?
A healthy, well-balanced diet can provide adequate fiber mainly if you eat your 5 A DAY and choose whole grain foods and potatoes in skins.
Below is an illustration of foods that together provide more than the recommended amount of fiber over a day. A 7-day meal planner that meets fiber recommendations can be found here https://www.nutrition.org.uk/attachments/article/881/SACN%20guidelines%20meal%20planner.pdf.
Fiber content (g)
|1 banana, sliced||100g||1.5|
|wholemeal toast (2 slices)||70g||4.7|
|Dinner||Baked potato with skin, tuna mayonnaise||180g||6.5|
|Salad (lettuce, tomato, and cucumber)||138g||1.7|
|and chopped almonds||13g||1.3|
|Total fiber intake||34.4|
Fiber for the under-2s
As a matter of fact, due to a lack of knowledge on children under 2 years, no firm guidance about how much fiber they need per day has been made.
Although, a varied diet from the age of about 6 months with increasing amounts of pulses, fruits, and vegetables is encouraged, hence, has is steadily increasing whole grains, although NHS choices advise to not give only wholegrain starchy foods to under 2s as they may fill the child up before they’ve taken in the calories and nutrients they need.
Fiber and Irritable Bowel Syndrome (IBS)
In the event that people with IBS are usually well aware that diet can play an important part in controlling symptoms, and are often advised to modify the amount of fiber in their diet.
For instance, the BDA recommends that if symptoms include constipation then gradually increasing fiber intake may help, particularly whole grains, oats, fruit, vegetables, and linseeds as these may help to soften stools and make them easier to pass.
However, If symptoms include diarrhea though it may be helpful to try reducing intake of some high fiber food such as wholegrain breakfast cereals and bread.
Obviously, there is no “one size fits all” diet for people with the condition. Keeping a food and symptom diary can help monitor your progress. If you need further help, ask your doctor to refer you to a healthcare professional with expertise in dietary management.
Although, resistant starch is a form of starch that cannot be digested in the small bowel.
As a result, it is a type of fiber. It is seen naturally in some foods such as potatoes, bananas, grains, and legumes and is also produced or modified commercially and incorporated into some food products.
However, human studies have shown that including foods rich in resistant starch within a meal is useful for controlling blood glucose and there is some evidence that it might help us to feel more full after meals, which could mean we snack less.
Here are some meal ideas to help you get more resistant starch into your diet:
- Jacket potato with baked beans
- Mixed bean salad made with couscous, brown rice, wholewheat pasta or cold potatoes in their skins and plenty of salad vegetable
- Lentil or chickpea curry served with brown rice and plenty of vegetables
- A banana sandwich made with wholemeal bread
- Vegetable chili with kidney beans and sweetcorn
- Snack on low-fat hummus with vegetable sticks
For more detailed information about resistant starch click here.