How to increase your fibre intake

Having established that fibre has definite benefits to offer, how can you make sure you get enough of it on a regular basis? Basically, there are three ways of upping your fibre intake, namely:through following a natural high-fibre diet (lots of fruit and vegetables, wholewheat bread, unrefined rice, etc)by eating fibre-enriched foodsby taking fibre extracts or supplements in the form of bran, pills, tablets, powders or granules.

It probably goes without saying that the first option is the healthiest. A natural high-fibre diet in which more unrefined plant foods and less foods of animal origin are eaten, is preferable not only because it ensures adequate intakes of vitamins and minerals, but because it also includes less animal fat - whereas the pill-popping method will merely increase the intake of indigestible fibre.

Eating fibre-enriched products - such as some breakfa^st cereals and home-baked muffins to which bran has been added - will certainly increase fibre intake, but will not necessarily rectify dietary imbalances. This is because most South African recipes for wholewheat home-baked products contain too much fat and sugar, which may improve the flavour but also markedly increases the kilojoules. However, it is possible to cut both the fat and sugar content to healthier levels when baking at home.

Fibre extracts are useful in the treatment of disease. They should only be used for medical reasons and not as foods, and must be taken under the guidance of a physician or dietitian. Insoluble extracts such as bran should always be used in combination with adequate water intake to treat constipation and related diseases. Soluble extracts, such as konjac-glucomannan, pectin or guar gum, are used to lower blood cholesterol levels and to control glucose levels in diabetic patients.

How much is enough?

Recommendations for fibre intake are based on those of developed populations in the past (before the escalation of the diseases of affluence) and on intakes of population groups at low risk for these diseases - such as rural, less developed populations and vegetarians.

On average, affluent Western populations presently consume 10 to 20g total dietary fibre per day; it has been recommended that this should be increased to between 30 and 40g per day. Our own research has shown that white South Africans on a typically Western diet eat approximately 2g total dietary fibre per 1000 kilojoules (kJ) per day - a figure which should be doubled. Based on this recommendation, a fairly active adult woman with a daily energy need of between 8000 and 9000 kJ should take in 32 to 36g dietary fibre per day, while a moderately active adult man with an energy need of 9000 to 11000 kJ should consume 36 to 44g fibre.

The table below shows that you can obtain approximately 40g of total dietary fibre by eating six small to medium portions of wholegrain cereals (which include wholewheat bread, brown rice and unrefined breakfast cereals), one medium portion of legumes (beans, peas, lentils), three medium portions of vegetables and two medium portions of fruit per day.

Foods (and portion sizes) that will provide approximately 40 g total dietary fibre per day

Food	Portion size	Total amount (g)	Dietary fibre (g) -
4 medium slices"wholewheat bread	1 slice: 95 X 90 X 10 mm = 35 g	140	12,5
1 portion All
Bran Flakes	125 ml	25	7,5
1 portion cooked brown rice	125 ml	70	0,9
1 portion cooked dried beans	125 ml	100	7,4
1 portion cooked broccoli	125 ml	75	3,1
1 portion grated raw carrots	125 ml	95	2,4
1 portion mixed raw salad	125 ml	50	0,8
1 medium apple	52 X 66 mm	150	2,6
1 medium orange	65 X 70 mm	180	3,6
TOTAL			40,8

Can you eat too much fibre?

Many fibrous plants contain organic acids that bind minerals such as calcium, magnesium, zinc and iron. Although this has caused some concern in the past, there is no evidence that people who eat natural high-fibre diets (such as vegetarians) have low mineral levels, probably because this type of diet is particularly rich in vitamins and minerals. Including about 40g dietary fibre a day in your diet is regarded as being perfectly safe. However, where caution is necessary is in the taking of fibre extracts.

One of the lesser-known effects of fibre-rich diets is an increase in flatulence. When fibre ferments in the large intestine it produces odourless gases, which are not dangerous to health but can cause concern in some people. (Incidentally, offensive odour is caused by gases which are produced as result of the breakdown of other substances in the large bowel - such as sulphur-containing proteins - which have escaped digestion in the small intestine.)

Fibre extracts - handle with care!

If a natural high-fibre diet does not solve the problem of constipation, try taking not more than three tablespoons (9-12g) of digestive bran, divided into three dosages, on a daily basis. (If you don't like the taste of bran au nature], you can improve the flavour by baking it for three hours at 100 °C.) At the same time, increase your fluid intake to at least two litres per day and decrease excessive fat intake. This ensures adequate hydration of the 'extra' fibre.

Beware of over-enthusiatic dosage with fibre extracts or concentrates, as this can be harmful. As a general guideline, a third of the prescribed dosage should be taken for a week and two thirds for another week before the whole amount is taken.

The 'fibre message'

All in all, then, there is agreement that fibre forms an important part of a healthy, balanced diet. High-fibre diets are easy to follow and inexpensive if natural foods are eaten in their unrefined forms.

Guidance from and education by dietitians, nutritionists and doctors, as well as increased advertising of high-fibre products, have brought the 'fibre message' to some sections of our population.

Sadly, however, in other sections the situation is in reverse. As South Africa's rural black people grow increasingly urbanized, so their diets are becoming lower in fibre and higher in fat - and more and more, the so-called 'diseases of affluence' are being seen among them. For the 'fibre message' to have any significant effect on the health of the majority of our population, it must therefore also reach the very people whose diets once gave them natural protection against the degenerative diseases of Western civilization.

When all is said and done, education is only worthwhile when put into practice. So unless you, the consumer, choose high fibre, unrefined foods in preference to refined ones and unless pressure is put on manufacturers to produce the healthier alternatives, medical research and nutrition education will be of little use. Ultimately it is up to you to make your voice heard and to combat the influences of society, lifelong nutritional habits and perhaps simple apathy, in order to put the fibre message into practice.

Worthwhile Sources of Dietary Fibre (Food Cereals & Fibre rating)

• Bread, brown: Fair
• Bread, wholewheat: Good
• Wheat bran: Excellent
• Pronutro: Excellent
• Kelloggs All Bran Flakes: Excellent
• Kelloggs Cornflakes: Good
• Oats: Good
• Oat bran: Excellent
• Weet-Bix: Good
• Maize meal, white: Fair
• Maize meal, unsifted: Good
• Popcorn, plain: Good
• Rice, brown: Fair
• Ryvita, Ryeking: Good
• Provita: Good