The actual amount of protein to be consumed daily to meet the daily requirement will depend upon the quality of dietary protein. The higher the quality, lower the requirement and vie-versa. It is to be expected that children require more protein per unit body weight than do adult, because of new tissues which are being laid down during growth are largely built form amino acids drawn from the dietary proteins. Thus a young child of 1-years requires 1.2g egg protein/kg or 2.0g of mixed vegetable per kg. Likewise, protein needs of women are greater during pregnancy and lactation than during pregnancy and lactation than during non-pregnant, non-lactating state.
It also must be emphasized that figures for protein requirement are valid only when other nutrients particularly calories in diet are adequate. In other words, the diet must be a well-balanced one. A mixed diet even solely based on plant proteins can meet their energy needs. For this the protein content of the diet should be such as to contribute around 10% of the total calorie.
For growing children and for women during pregnancy and lactation, the protein requirements are relatively greater and it is desirable some animal foods which have protein of high nutritive value of included in the diet of these groups of population particularly if the protein concentration in the diet is low (containing low protein cereals, roots, little of pulse, etc.).
The best source of animal protein for growing children is milk. Milk also provides a good amount of calcium which is normally lacking in vegetarian diets. Eggs also can be used as a source of good quality protein whenever possible. Besides providing good quality protein it provides a good amount of a wide range of other nutrients, particularly B12 which is absent in vegetable foods. Skimmed milk is a rich source of good quality protein. Fish also is a good source of protein whenever available and acceptable and should be included in the diet, particularly of older children and adults.
In devising an inexpensive well balanced diet in India, economic considerations often preclude the inclusion of milk or other animal foods like cereals and pulses and vegetables can be relatively inexpensive and at the same time can provide a mixture of proteins with nearly as good as amino acid pattern as that of expensive animal foods.