Sugar and starch give energy. Sugar and starch are carbohydrates. Fibre is another carbohydrate, although it does not provide energy. Fibre helps the movement of food in the intestine, and so it prevents constipation. Fibre which cannot be digested by humans is also known as Cellulose and Roughage. Pectin is another carbohydrate, which is found in ripe fruit. It causes jam to set. Carbohydrates contain the elements carbon, hydrogen, and oxygen.

Sugar

Pectin.

Sugars are found in honey, fruit (both fresh and dried) soft drinks, milk and sugar.

Starches are found in cereals, pasta, flour, bread, potatoes, root and pulse vegetables.

Cellulose or Dietary Fibre is found in whole cereals, wholemeal bread, outer skins of fruit and vegetables, brown rice and oatmeal. In refined foods the dietary fibre is removed during processing e.g. wholemeal flour contains fibre but white flour does not.

Pectin is found in ripe fruit.

The functions of carbohydrates are:

Nutritionists believe that the amount of sugar eaten in the western countries needs to be decreased and the amount of fibre needs to be increased. The Recommended Dietary Allowance (RDA) of fibre is now 30g per day. We in the western world eat about half the recommended amount-15g per day. Refined foods and processed foods often lack fibre. Unrefined foods have a high fibre content. The more processing is carried out on food the less fibre it contains.

Carbohydrate deficiency diseases rarely occur, as carbohydrate is present in a wide variety of foods. However we should not eliminate carbohydrates completely from our diet because the body then uses protein as an energy source.

Some foods contain only sugars. They do not contain any other nutrients. They provide empty kilocalories. Examples are fizzy drinks and table sugar. Too much sugar in the diet causes tooth decay.