CALORIES

(food). Owing to the fact that the changes which food undergoes in the body are due to oxidation, the amount of heat Jibe rated by any food when it is burnt is an approximate measure of the amount of energy it will yield when eaten. The large calorie (see CaLorir) is therefore taken as a unit of nutriment, and by burning a weighed amount of food in a cal or- {meter the number of calories, or, in other words, the amount of nutriment, it will yield may be readily determined. It should be noted, however, that the results thus obtained are not a complete indication of food-value. ‘Thus a pound of butter will yield almost six times as many calories as a pound of beef, but one could not live on butter alone because it contains only a negligible quantity of protein, in which constituent beef is very rich, and protein is nece ary in order to repair the daily wear and tear of the ti ues, and, therefore, to maintain life. The calorie, however, is the only absolute standard by which foods can be compared, and it is therefore of great value if used intelligently, The number of calories needed daily by the adult varies from fifteen to twenty per pound of normal weight. The greater the physical activity, the greater the number of calories required.