weight, so a calory is the unit for measuring heat. A calory is the amount of heat necessary to raise the temperature of one liter of water one degree centigrade. The table following the charts is tabulated from them, and shows in more compact form the data they contain. It will be seen from these tables that vegetable foods are generally high in carbohydrates, and animal foods are generally high in fat, while the amount of protein may run as high as 25 per cent in either animal or vege table foods, the amount varying greatly in different foods. Carbohydrates. are the cheapest source of energy and heat, and hence are the more natural source for the greater part of these two necessities of the human body. It is figured that a man at hard work requires 100 grams of protein matter, 100 grams of fat, and 520 grams of carbohydrates to meet the demands of the system. The following two tables have been arranged to show the cheapest source of protein and the cheapest source of heat and energy in the foods mentioned Chart 14. Composition, Functions, And Uses Of Food. US Department of Agriculture Office of Experiment Stations Prepared by C.F. LANGWORTHY Expert in charge of Nutrition Investigations FUNCTIONS AND USES OF FOOD. CONSTITUENTS OF FOOD. Food is that which, taken into the body, builds tissue or yields energy. in the previous tables. The first table shows the amount of protein in each of these different foods that can be furnished for 1 cent, and the foods are arranged in the order of the amounts supplied at that price as estimated upon the cost per pound given in the preceding column. The second table is arranged in a similar manner with reference to the heat and energy furnished. Neither table shows the relative amount of food value obtained for the same price. As heat and energy and fiber building material are all necessary for the support of life, the two tables must be considered together in deter Chart 15 Dietary Standards. U.S.Department of Agriculture Office of Experiment Stations Prepared by C.F. LANGWORTHY Expert in charge of Nutrition Investigations DIETARY STANDARDS. DIETARY STANDARD FOR MAN IN FULL VIGOR AT MODERATE MUSCULAR WORK. mining the relative food values. The fuel value of food may be determined approximately from the analysis. To determine the number of calories per pound, multiply the sum of the per cents of the carbohydrates and protein by 18.6. To this product add the product of the per cent of fat multiplied by 42.2. Farmers Bulletin No. 142, entitled, Principles of Nutritive Food Values, forty-eight pages, may be obtained by addressing Division of Publications, United States Department of Agriculture, Washington, D. C. -23 F C |