There are, broadly speaking, two types of fibre: insoluble fibre, which is the most familiar form, and soluble fibre.
Insoluble Fibre is what most people call "fibre", or "roughage". It is not digested by the body: instead, its function is to bulk up food and help it to pass through the digestive tract. A healthy, high-fibre diet will allow stools to travel through the body quickly. Slow passage of food through the digestive tract causes stools to dry out and become hard.
How much fibre you need depends on your body, but in general, most people eat too little fibre. Our ancestors did not refine foods, and almost everything they ate contained fibre. In contrast, the modern diet affords little opportunity for a healthy intake of fibre.
Fibre is particularly essential for people on a weight-loss diet. Low-calorie diets are often low in fibre, so the products below should help to redress this balance.
Figs and prunes are well-known for being a good source of fibre. These and others can often be found in a convenient dried or semi-dried form. The new Ready-to-Eat packs of dried fruit such as Crazy Jack Apricots are soft and easy to digest.
Soluble fibre is less familiar to most people, but it has come to prominence in recent times due to a number of associated health benefits. As its name suggests, soluble fibre dissolves in water to form a thick gel. This traps moisture and carbohydrates, which is the ideal environment for bacteria (the famous "friendly bacteria") to break down food.
In addition, scientific evidence strongly suggests that soluble fibre helps reduce LDL cholesterol, and can thus reduce the risk of heart disease. The mechanisms by which this occur are still being studied, but the evidence is strong. It is also believed that soluble fibre, by trapping carbohydrates, releases those carbohydrates slowly, thus preventing surges in blood sugar levels.