Proteins are the indispensible constituents of the diet. Proteins are made up of amino acids. Amino acids are needed for replacement and growth of the body parts. Amino acids are classified as essential and non essential amino acids. Essential amino acids cannot be synthesized by the body and must be taken through foods whereas non essential amino acids can be synthesized by the body.
The ICMR recommends 1gm of protein/ Kg of body weight for adults. The amount of protein should be increased for children, pregnant and lactating mothers by 1.5- 2 g/kg body weight.
Sources of Protein
Animal sources: eggs, milk and milk products, fish, meat.Plant sources: pulses, cereals, dry fruits, beans nuts etc.
Functions of Proteins
• Protein helps in synthesis of enzymes, immunoglobulin, plasma proteins and hormones in the body• Protein helps in growth and repair of body tissues• Proteins are secondary sources of energy during deficiency of carbohydrates and fats. (Provides 4 Kcals/gm)• Proteins help in forming haemoglobin• Proteins help in antibody formation
Digestion and absorption:
The hydrolysis of proteins in the gastro intestinal tract is accomplished by proteases secreted in gastric juice and pancreatic juice and also by proteases present in the intestinal mucosa.