Proteins – are very important in our food for growth and repair of the human body. They are organic compounds that are made up of carbon, oxygen, nitrogen, and hydrogen. Several proteins that also contain sulphur and phosphorus. Proteins are very important for the growth of children and the teenagers. They are also needed for maintenance and making good the wear and tear of body tissues in adults. Proteins are also made up of nitrogen, which contains compound called amino acids. There are more than 20 of these amino acids and they all occur in almost all proteins. Most of the proteins, which are required to perform different functions in our body are prepared within the body from the unbounded amino acids.

The proteins consumed in our food are not used by our body in their original form because proteins are insoluble in water and secondly they are very complex molecules. When the food is digested in small intestine, the proteins are present in the food are broken down into simpler substances called as amino acids. The amino acids are water soluble and less complex molecules. The amino acids thus formed are absorbed from the intestine into the blood. The blood carries these three free amino acids to the various body cells where they are regrouped to form specific proteins, such as skin, muscle, blood and bones.

Proteins obtain from plant sources and animal sources. There are some sources of plant proteins are beans, ground nuts, whole cereals, such as wheat, maize, and pulses. Several sources ftom animal proteins are eggs, fish, lean meat (meat without fat), cheese, and milk. These are all body buildings foods. These proteins are particularly or necessary for children.

Our body requires different types of proteins, such as enzyme proteins for digestion like pepsin and trypsin, hormones proteins are used in regulating various body functions like insulin, transport proteins are used in carrying different substances from the blood to the various tissues of the body like haemoglobin, contractile proteins are used for contraction of muscles like myosin and actin, structural proteins are used to form the structural elements of the cells and tissues of our body like collagen, and protrctive proteins are used to help in fighting with several indections in our body like gamna globulins.

The protein requirement for a normal adult is 1 gram per kilogram in our body and weight per day. Growing children require more protein than body weight.