Eat more fibre.
Dietary fibre — found mainly in fruits, vegetables, whole grains and legumes — is probably best known for its ability to prevent or relieve constipation. But foods containing fibre can provide other health benefits as well, such as helping to maintain a healthy weight and lowering your risk of diabetes and heart disease.
Selecting tasty foods that provide fibre isn’t difficult. Find out how much dietary fibre you need, the foods that contain it, and how to add them to meals and snacks.
What is dietary fibre?
Dietary fibre, also known as roughage or bulk, includes all parts of plant foods that your body can’t digest or absorb. Unlike other food components, such as fats, proteins or carbohydrates — which your body breaks down and absorbs — fibre isn’t digested by your body. Instead, it passes relatively intact through your stomach, small intestine, colon and out of your body.
Fibre is commonly classified as soluble (it dissolves in water) or insoluble (it doesn’t dissolve):
- Soluble fibre. This type of fibre dissolves in water to form a gel-like material. It can help lower blood cholesterol and glucose levels. Soluble fibre is found in oats, peas, beans, apples, citrus fruits, carrots, barley and psyllium.
- Insoluble fibre. This type of fibre promotes the movement of material through your digestive system and increases stool bulk, so it can be of benefit to those who struggle with constipation or irregular stools. Whole-wheat flour, wheat bran, nuts, beans and vegetables, such as cauliflower, green beans and potatoes, are good sources of insoluble fibre.
Most plant-based foods, such as oatmeal and beans, contain both soluble and insoluble fibre. However, the amount of each type varies in different plant foods. To receive the greatest health benefit, eat a wide variety of high-fibre foods.
Benefits of a high-fibre diet
A high-fibre diet has many benefits, which include:
- Normalises bowel movements. Dietary fibre increases the weight and size of your stool and softens it. A bulky stool is easier to pass, decreasing your chance of constipation. If you have loose, watery stools, fibre may also help to solidify the stool because it absorbs water and adds bulk to stool.
- Helps maintain bowel health. A high-fibre diet may lower your risk of developing haemorrhoids and small pouches in your colon (diverticular disease). Some fibre is fermented in the colon. Researchers are looking at how this may play a role in preventing diseases of the colon.
- Lowers cholesterol levels. Soluble fibre found in beans, oats, flaxseed and oat bran may help lower total blood cholesterol levels by lowering low-density lipoprotein, or “bad,” cholesterol levels. Studies also have shown that fiber may have other heart-health benefits, such as reducing blood pressure and inflammation.
- Helps control blood sugar levels. In people with diabetes, fibre — particularly soluble fibre — can slow the absorption of sugar and help improve blood sugar levels. A healthy diet that includes insoluble fibre may also reduce the risk of developing type 2 diabetes.
- Aids in achieving healthy weight. High-fibre foods generally require more chewing time, which gives your body time to register when you’re no longer hungry, so you’re less likely to overeat. Also, a high-fibre diet tends to make a meal feel larger and linger longer, so you stay full for a greater amount of time. And high-fibre diets also tend to be less “energy dense,” which means they have fewer calories for the same volume of food.
Another benefit attributed to dietary fibre is prevention of colorectal cancer, however, the evidence that fibre reduces colorectal cancer is mixed.
How much fibre do you need?
How much fibre do you need each day? The Institute of Medicine, which provides science-based advice on matters of medicine and health, gives the following daily recommendations for adults:
|Age 50 or younger||Age 51 or older|
|Men||38 grams||30 grams|
|Women||25 grams||21 grams|
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