Fibre (roughage) is the part of plant food that is not digested. It stays in your gut and is passed in the stools (faeces). Fibre adds bulk to the stools. This helps your bowels to work well, and helps to prevent some bowel and anal conditions.
Why is fibre important?
Stools (faeces or motions) are usually soft and easy to pass if you eat enough fibre, and drink enough fluid. We should aim to eat at least 18 grams of fibre per day. (The average person in the UK eats only about 12 grams of fibre each day.) A diet with plenty of fibre:
- Will help to prevent and treat constipation.
- Will help to prevent some bowel conditions such as diverticula, haemorrhoids (piles) and anal fissure (a painful condition of the anus).
- May help you to lose weight. Fibre is filling but it has no calories and is not digested.
- May reduce the risk of developing bowel cancer.
- May help to lower your blood lipid (cholesterol) level.
These include the following:
- Wholemeal or whole wheat bread, biscuits and flour.
- Fruit and vegetables. Aim to eat at least five portions of a variety of fruit and vegetables each day. One portion is: one large fruit such as an apple, pear, banana, orange, or a large slice of melon or pineapple; OR, two smaller fruits such as plums, satsumas, etc; OR, one cup of small fruits such as grapes, strawberries, raspberries, cherries, etc; OR, one tablespoon of dried fruit; OR, a normal portion of any vegetable (about two tablespoons); OR, one dessert bowl of salad.
- Wholegrain breakfast cereals such as All-Bran®, Bran Flakes®, Weetabix®, Shredded Wheat®, muesli, etc. A simple thing like changing your regular breakfast cereal can make a big difference to the amount of fibre you eat each day.
- Brown rice, and wholemeal spaghetti and other wholemeal pasta.
Fibre supplements (sometimes called bulk-forming laxatives)
You may be advised by your doctor to take extra fibre supplements if you have constipation or other bowel problems such as irritable bowel syndrome. Several are available. You can buy them at pharmacies or health food shops:
- Unprocessed bran is a cheap fibre supplement. You can sprinkle bran on breakfast cereals, or mix it with fruit juices, milk, stews, soups, crumbles, pastries, scones, etc. However, bran may not be suitable for you (see below).
- Other fibre supplements include ispaghula husk (psyllium), methylcellulose, sterculia, wheat dextrin, inulin fibre, and whole linseeds (soaked in water). There are various branded products that contain these supplements (a pharmacist can advise).
Note: have lots to drink when you eat a high-fibre diet or fibre supplements. Drink at least two litres (about 8-10 cups) per day. This is to prevent a blockage of the gut, which is a rare complication of eating a lot of fibre without adequate fluid.
You may find that if you eat more fibre or fibre supplements, you may have some bloating and wind at first. This is often temporary. As your gut becomes used to extra fibre, the bloating or wind tends to settle over a few weeks. However, some people report that a high-fibre diet causes some persistent mild symptoms such as mild pains and bloating. In particular, some people with irritable bowel syndrome find that an increase in fibre makes symptoms worse. But, this may be related to the type of fibre you take. There are two main types of fibre - soluble fibre (which dissolves in water) and insoluble fibre. It is probably soluble fibre rather than insoluble fibre that is most helpful, especially when aiming to ease symptoms of irritable bowel syndrome. Bran and other insoluble-based fibre may actually make symptoms worse in some people.
So, if you increase fibre, you may prefer to have more soluble rather than insoluble fibre.
- Dietary sources of soluble fibre include oats, ispaghula (psyllium), nuts and seeds, some fruit and vegetables and pectins. A fibre supplement called ispaghula powder is also available from pharmacies and health food shops.
- Insoluble fibre is chiefly found in corn (maize) bran, wheat bran and some fruit and vegetables.
Fibre Content of Some Common Foods
All-Bran® - one medium sized bowl (40 g)
Shredded Wheat® - two pieces (44 g)
Weetabix® - two pieces (37.5 g)
Muesli (no added sugar) - one medium sized bowl (45 g)
Fruit 'n' Fibre® - one medium sized bowl (40 g)
Porridge - one medium sized bowl (250 g)
Cornflakes - one medium sized bowl (30 g)
|Fibre in grams (g)
|Pasta and Rice
Pasta (plain, fresh) - one medium portion (200 g)
Brown rice (boiled) - one medium portion (200 g)
White rice (boiled) - one medium portion (200 g)
|Fibre in grams (g)
Wholemeal bread - two slices (70 g)
Brown bread - two slices (70 g)
Granary bread - two slices (70 g)
White bread - two slices (70 g)
|Fibre in grams (g)
|Vegetables / Fruit / Nuts
Baked beans (in tomato sauce) - half can (200 g)
Red kidney beans (boiled) - three tablespoons (80 g)
Peas (boiled) - three heaped tablespoons (80 g)
French beans (boiled) - four heaped tablespoons (80 g)
Brussel sprouts (boiled) - eight sprouts (80 g)
Potatoes (old, boiled) - one medium size (200 g)
Carrots (boiled) - three heaped tablespoons (80 g)
Broccoli (boiled) - two spears (80 g)
|Fibre in grams (g)
|Apricots (semi-dried) - three whole (80 g)
Prunes (semi-dried) - three whole (80 g)
Pear (with skin) - one medium (170 g)
Orange - one medium (160 g)
Apple (with skin) - one medium (112 g)
Raspberries - two handfuls (80 g)
Banana - one medium (150 g)
Strawberries - seven strawberries (80 g)
Grapes - one handful (80 g)
|Almonds - 20 nuts (33 g)
Peanuts (plain) - one tablespoon (25 g)
Brazil nuts - 10 nuts (33 g)
Further reading & references
- British Nutrition Foundation
- Approximate dietary fibre content of selected foods, MeReC Bulletin, Vol 14, No 06, 2004, Supplement
- Ford AC, Talley NJ, Spiegel BM, et al; Effect of fibre, antispasmodics, and peppermint oil in the treatment of irritable bowel syndrome: systematic review and meta-analysis. BMJ. 2008 Nov 13;337:a2313. doi: 10.1136/bmj.a2313.
|Original Author: Dr Tim Kenny||Current Version: Dr Tim Kenny|
|Last Checked: 05/01/2011||Document ID: 4248 Version: 40||© EMIS|
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