NUTRITION LABORATORY. 275 



are summarized and compared. Emphasis is laid upon the fact that " normal" 

 and "average," when used in considering data obtained with children, are not 

 synonymous terms, owing to the large proportion of underweight children. 

 The suggestion is made that, for a basis of comparison, the weight as compared 

 with height is more logical than the weight as compared with age. 



Charts are given comparing the minimum or basal heat production of new- 

 born infants on the basis of age ; also a chart showing the heat production of a 

 normal infant at various times during a period of 4 years. The observations 

 with the normal children studied are summarized for boys and girls separately 

 in a nimaber of graphic comparisons, in which the basal heat production per 

 24 hours is considered on the bases of age, body-weight, and body-surface. 

 A comparison is made of the data for boys and girls to determine the influence 

 of sex, and of both boys and girls with results for men and women to show the 

 difference between the metabolism in the period of growth and in adult hfe. 

 The influence of approaching puberty is also considered. 



"From these charts it is clear that at a very early age, i.e., with low weights, 

 the metabohsm is specifically low. It then rises rapidly until the child's 

 weight has increased to approximately 10 kilograms, when it is at its maximum 

 per unit of weight and per unit of area. There is next a steady decrease until 

 approximately 30 to 40 kilograms, when the early adult period begins," 

 " It must be borne in mind that in the making of such curves there is danger of 

 misinterpretation as to the fixity of the lines, and it should be remembered 

 that they represent trends only." "Up to 8 kilograms no differences in the 

 sexes are to be noted, but thereafter the boys have a somewhat higher heat 

 production on the whole, thus indicating a specifically somewhat higher 

 metabolism with the growing boy than with the growing girl." 



The details of the earlier studies with infants are given in PubKcations Nos. 

 201 and 233 of the Carnegie Institution of Washington. The complete results 

 of the later investigations, including those with the older boys and girls, are 

 being prepared for publication. 



(10) Human vitality and efficiency under prolonged restricted diet. Francis G. Benedict, 



Walter R. Miles, Paul Roth, and H. Monmouth Smith. Carnegie Inst. 

 Wash. Pub. No. 280 (1919). 



A detailed abstract of the results obtained in the study of human vitality 

 and efficiency with a prolonged restriction of diet was given in the previous 

 annual report in reviewing a preliminary report of the findings of this research. 

 (See "The effects of a prolonged reduced diet on twenty-five college men" in 

 the annual report of the Director for 1918.) It thus appears unnecessary to 

 give a further abstract of the results here. 



(11) The energy content of extra foods. (Second paper.) Cornelia Golay Benedict and 



F. G. Benedict. Boston Med. and Surg. Journ., 181, 415 (1919). 



A report of the latest results of the study on the energy content of "extra 

 foods" is given in the second paper of this series, in which a considerable 

 number of food materials used on picnics, automobile tours, and for incidental 

 meals are treated of. The energy content is given of ohves and ohve products, 

 sardines, nuts, potato chips, doughnuts, confectionery (especially the "penny 

 candies"), cream cheeses, popcorn, crackers, and pretzels. In view of the 

 increasing use of refined sugar in American homes, the caloric value of ordinary 

 servings of granulated sugar and the weights and sizes of various lump sugars 

 are also discussed. The method followed in determining the energy values 

 reported in the fii'st paper, i.e., the direct determination of the caloric value by 

 means of the bomb calorimeter, was used for these food materials. 



