Most foods that we eat contain some amount of carbohydrates. Carbohydrate is the nutrient that we consume daily in the maximum amount. These, therefore, make up the bulk of our diet. Carbohydrates are either naturally present as in rice, wheat, fruits, potato, honey, etc., or added to food in the form of sugar such as ice-cream, cold drinks, tea, coffee and so on.
There are some carbohydrates which are complex like starches which the body has to digest in order to use them. There are others which are simpler in nature like glucose, which can be used by the body directly. Sugar which is so commonly used is also an easily digestible carbohydrate.
Functions of Carbohydrates:
Ø Energy giving action: Carbohydrates are the cheapest source of energy. Each gram of carbohydrate gives four kilo calories of energy to the body. Although fats and proteins also provide energy, the intake of carbohydrates is much greater and so it is the most important source of energy to us.
Ø Protein-sparing action: Proteins are required by the body mainly for growth and development purposes. At the same time, they can also provide energy to the body when there is a short supply of carbohydrates and fats. However, if proteins are used exclusively to give energy it is a waste, because they are mainly derived from expensive foods. It is, therefore, important that we should have sufficient amount of carbohydrates and fats in our diets. This will spare the proteins for their main task of growth and development which carbohydrates and fats cannot perform.
Ø Fat utilizing action: Carbohydrates when present in adequate amounts in the diet help in the proper utilization of fats in the body.
Ø Digestive action: These are some forms of carbohydrates called fiber or roughage which are not digested by the body and therefore do not provide any energy. These are however, important to us. They give bulk to the diet and so help in normal movement of the food in the gastro-intestinal tract. This helps to prevent constipation. These are present in coarse grains, green leafy vegetables, etc.
Sources:
Sugar and honey are pure carbohydrates. Cereals, pulses, roots and tubers like potatoes, sweet potatoes, beet root, yam, etc., are very rich sources of carbohydrates. Fruits especially bananas, mangoes, pineapples and grapes are also a good source of carbohydrates.
Effects of deficiency/excess on the body:
The effects of carbohydrates on the human body can be related their deficiency or excess in diet. Lack of carbohydrates in the diet basically causes lack of energy. This leads to underweight, tiredness and poor working efficiency.
If our diet has excess carbohydrates, it is converted into fat and stored in our body. Therefore, and increased intake of carbohydrates leads to overweight. This in turn can be one of the causes for other diseases like heart attack, diabetes, high blood pressure, etc.