Fiber is an essential part of a healthy diet and vital for your body to function properly. fiber helps the digestive system to process food and absorb nutrients. However, it is not something the body can absorb - this means that it is not a nutrient and contains no vitamins.

Fiber is obtained from plant-based foods. There are two types of fiber: insoluble and soluble.

Insoluble Fiber

Insoluble fiber contains the compounds cellulose, hemicellulose and lignin. These help the bowel to pass food by making stools soft and bulky. This type of fiber helps prevent constipation.

Insoluble fiber is found in the following foods:

• beans
• brown rice
• fruits with edible seeds
• lentils
• maize
• oats
• pulses
• wholegrains, including bread, cereals and flour

Soluble fiber

Soluble fiber contains gums and pectin. This type of fiber controls blood sugar. It can be found in all fruit and vegetables, but the following are rich sources:

• apples
• barley
• citrus
• legumes
• oats
• pears
• strawberries

Soluble fiber slows down the rate at which glucose is absorbed from food in the bloodstream. This gives the body more time to process carbohydrates, leading to lower blood sugar levels and better carbohydrate metabolism. Therefore adequate amounts of fiber in the diet will help to control blood sugar levels and avoid surges of sugar or insulin.

A high-fiber diet is one of the best ways to avoid putting weight on. It is thought that fiber can support weight loss in the following ways:

• Fiber adds bulk to a meal making it more satisfying and filling
• Fiber slows down the digestive process and thus delays hunger for longer, making the body consume fewer calories
• Fiber can prevent food cravings because it slows the absorption of glucose, which helps to regulate blood sugar levels
• Fiber is not absorbed by the body so less of the calories consumed will be absorbed by the body

Wheat bran is one of the least effective forms of fiber and can prevent absorption of vitamins, minerals and other nutrients. The fiber present in oats, vegetables, fruit, lentils and other pulses is much more effective and kinder to your gut.