Food allowances or dietary standards for children differ from those for adults in that they must provide not only for all expenditures but also for growth. Recently a considerable number of accurate measurements of energy expenditure of children have been made - especially of infants in the first year of life and of boys twelve and thirteen years old. These data whether obtained by the method of direct or indirect calorimetry give precise information as to the energy output at the time of the experiment, but naturally the observations cannot cover the entire 24 hours of the day, nor can experiments of a few hours' duration give any direct information as to how much the intake must exceed the output in order to provide amply for a normal rate of growth. Observations of the unrestricted food consumption (ordinary dietary studies) of healthy children who are making normal growth, and nitrogen balance experiments which show both gain in weight and storage of nitrogen (growth of protein tissue) may be expected to furnish evidence of some value though of a somewhat inferential nature. As a result of compilation and study of all available data whether of dietary studies, nitrogen balance experiments, observations of the respiratory exchange, or direct measurements of energy output, the following standards are suggested:

Food Allowances For Healthy Children (Gillett)

In earlier allowances no distinction was made between boys and girls below ten years of age. The averages of recorded data show, however, a slightly higher energy exchange (or metabolism) in boys than in girls of the same age, though the difference is often less than the range allowed to cover differences of size and activity at a given age. Beyond 10 years of age, the energy exchange in boys evidently increases more rapidly than in girls, probably because of their greater restlessness and muscular activity through this period of development and their greater average rate of growth during and after the fifteenth year.

In this connection the accompanying table adapted from that of Manny based on data from Holt, Burt, and Boas is of interest.

Average Weights And Rates Of Growth Of Boys And Girls At Different Ages (Manny)

Children, like adults, will vary in muscular activity and this will influence their energy requirements irrespective of other conditions. Among other conditions to be considered are differences in size and physical development among children of the same age and sex. Children of more than average size, if normally active and not over-fat, will require somewhat more food than an average child of the same age. An estimate of energy requirement per unit of weight at different ages has been given in Chapter VII (Conditions Governing Energy Metabolism And Total Food Requirement. Basal Metabolism Of The Adult) (page 196). A child who has become . somewhat emaciated, either through rapid growth * or other causes, should have a larger food allowance than would ordinarily be required either for his age or for his weight.

In calculating the food requirements of a family it is best not to estimate the needs of other members in terms of that of the man of the family (because men on account of the great differences in activity of their occupations are likely to be more variable in their energy requirements than are children of any given age) but rather to estimate the Calories for each member of the family separately according to his or her own needs and then sum up the total. Not infrequently other members of the family may require more food than the man, especially if he be of less than average size and engaged in sedentary or other light work.