Foods, their selection and preparation

Food is any material which when eaten is digested, absorbed, and used to build and re¬ place body material or to provide energy. Source of Energy. Food must supply en¬ ergy for bodily activity. Some energy is needed in just living, in maintaining those internal functions which run so smoothly that we are scarcely aware of them. Breath¬ ing, the beating of the heart, the circulation NUTRIENTS AVAILABLE FOR CIVILIAN CONSUMPTION PER PERSON PER DAY, U. S., 1 9 4 2 - 4 5 AVERAGE, 1946, AND 1948 ( 1935-39 = 100 ) 1935-39 PERCENT OF 1935-39 AVERAGE FOOD ENERGY PROTEIN FAT CARBOHYDRATE CALCIUM IRON VITAMIN A THIAMINE ( VITAMIN Bi ) RIBOFLAVIN NIACIN ASCORBIC ACID ( VITAMIN C ) 3,250 ' CAL i. 0.90 13.8 MG. 8,100 INT'l. UNITS 1.54 MG. 1.86 MG. ! 5.4 MG. MG. * DATA FOR 1948 ARE PRELIMINARY Changing Food Habits • Nutrition education helped to change food habits during this period of the blood, all require energy. Energy is needed also to maintain normal body tem¬ perature. To this basic requirement must be added enough energy for conscious physical activ¬ ity. Sitting, standing, walking, running, working, or playing all require energy in varying amounts. Unless this energy is pro¬ vided in the food, body tissues are burned to supply it. In reducing diets this consump¬ tion of body fat may be desirable provided the diets carry the essential building and regulating foods. But, under normal con¬ ditions, the food should supply the daily needs for energy. The amount of energy required varies with the size of the individ¬ ual, the amount of body surface, the sur¬ rounding temperature, and the amount of physical activity. Body Building. Body tissues and fluids, muscle, bone, blood, and lymph are built and kept in repair from the materials provided by food. Food should supply body-building materials in the right forms and amounts. The demand for body-building foods is greatest during the years of most rapid growth, but there is a basic demand at all ages for building and repair material. In gen¬ eral this demand varies with the weight. Regulating Body Functions. Under nor¬ mal conditions, the many complex functions of the body are controlled without conscious interference. Digestion, breathing, and the heartbeat go on continuously without con¬ scious attention on our part. These un¬ conscious activities are controlled by the maintenance of the normal composition of important body tissues and fluids. The normal water content of the body is important to many functions. The protein must provide the building units for blood and other fluids that control vital organs as well as for muscle and bone. The blood and lymph must contain just the right proteins for building the antibodies that provide pro¬ tection from disease. Fats and carbohydrates are necessary in small amounts to functioning body cells. Traces of minerals are essential to important body functions. Some vitamins initiate and regulate chemical changes in body fluids. COMPOSITION OF FOOD