Diet – fibre; Roughage; Bulk; Constipation – fibre
Fibre is a substance found in plants. Dietary fibre, which is the type of fibre you can eat, is found in fruits, vegetables, and grains. It is an important part of a healthy diet.
Dietary fibre adds bulk to your diet. Because it makes you feel full faster, it can help with weight control. Fibre aids digestion and helps prevent constipation. It is sometimes used for the treatment of diverticulosis, diabetes, and heart disease.
There are two forms of fibre: soluble and insoluble.
Soluble fibre attracts water and turns to gel during digestion. This slows digestion. Soluble fibre is found in oat bran, barley, nuts, seeds, beans, lentils, peas, and some fruits and vegetables. Research has shown that soluble fiber lowers cholesterol, which can help prevent heart disease.
Insoluble fibre is found in foods such as wheat bran, vegetables, and whole grains. It appears to speed the passage of foods through the stomach and intestines and adds bulk to the stool.
Eating a large amount of fibre in a short period of time can cause intestinal gas (flatulence), bloating, and abdominal cramps. This problem often goes away once the natural bacteria in the digestive system get used to the increase in fibre. Adding fibre to the diet slowly, instead of all at one time, can help reduce gas or diarrhea.
Too much fibre may interfere with the absorption of minerals such as iron, zinc, magnesium, and calcium. In most cases, this is not a cause for too much concern because high-fiber foods tend to be rich in minerals.
On average, Canadians now eat about 16 grams of fibre per day. The recommendation for older children, adolescents, and adults is to eat 21 to 38 grams of fibre each day. Younger children will not be able to eat enough calories to achieve this amount, but it is a good idea to introduce whole grains, fresh fruits, and other high-fiber foods.
To ensure that you get enough fibre, eat a variety of foods, including:
- Dried beans and peas
- Whole grains
Add fibre gradually over a period of a few weeks to avoid stomach distress. Water helps fibre pass through the digestive system. Drink plenty of fluids (about eight glasses of water or noncaloric fluid a day).
Taking the peels off fruits and vegetables reduces the amount of fibre you get from the food. Fibre-rich foods offer health benefits when eaten raw or cooked.
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Thompson M, Noel MB. Nutrition and family medicine. In: Rakel RE, Rakel DP, eds. Textbook of Family Medicine. 9th ed. Philadelphia, PA: Elsevier; 2016:chap 37.
US Department of Health and Human Services. US Department of Agriculture. 2015-2020 Dietary Guidelines for Americans. 8th ed. health.gov/dietaryguidelines/2015/guidelines/. Accessed July 25, 2018.