In the first paper of the series on the food requirements of children the total caloric need throughout the entire period of growth was discussed in detail. The next step in the consideration of food needs is a study of the distribution of the total calories necessary. This involves the estimation of the required amounts of fat, carbohydrate and protein to be supplied in the daily diet and the relative proportions of each of these. When the total caloric need is known the proportion of the different constituents is most concisely expressed by the percentage of fat, carbohydrate and protein which are given.
All three of these nutritive substances are sources of energy. There are, however, other important considerations which affect the amount of each one of them in the diet. Especially is this true of the protein. Before considering the other food elements, it is necessary, first, to establish
HOLT LE, FALES HL. THE FOOD REQUIREMENTS OF CHILDRENII—PROTEIN REQUIREMENT. Am J Dis Child. 1921;22(4):371–380. doi:10.1001/archpedi.1921.04120040046004