{ { Solvent for food. { In all vegetables { Carries food to { { blood. V. { { Carries off waste. Water { { Helps to regulate { { temperature. { In all animal foods { Aids digestion. { { Aids tissue building. =Overuse of Carbohydrates.=—If too much sugar and starch are eaten, fermentation may take place and interfere with digestion. Too much sugar and starch overworks the liver. Because sweet foods have the quality of satisfying the appetite very readily they should not be taken to satisfy hunger, but should rather be eaten after sufficient body building and body regulating foods have been taken to meet the body’s need for such foods. The custom of serving the sweet food at the last of the meal is in harmony with this dietetic principle. It is important that children should form sane habits of eating sweet foods. The practice of using large amounts of sugar on cereals, cooked fruits, and in beverages should be discouraged. The overuse of sugar irritates the lining of the digestive tract. This is caused by the abstraction of water from the mucous lining. Sugar is one-sided in its value, consequently it is much wiser to obtain a high percentage of heat from foods which serve other purposes as well. =Protein Foods.=—The first class of foods, the proteins, includes those which have tissue building for their chief purpose. They are essential for maintenance and for body growth, as they are the only source of nitrogen. Therefore they are necessary for the growing child and for the athlete in the development of strong, vigorous muscles. The more easily digested protein foods are advised for the tubercular patient whose muscles and tissues have become debilitated by disease. Proteins are required by each individual, but in varying amounts, to suit age, occupation, condition of system, and climate. The value of a mixed protein diet is urged by the best authorities rather than the diet which contains but one protein food. =Overuse of Protein Foods.=—It is true that a high percentage of illness is caused by an accumulation of wastes in the body. It is also true that protein foods leave a higher percentage of waste material in the body than any other class of foods. It follows, then, that an overuse of protein foods overworks the excretory organs and tends to weaken them. The weakened excretory organs are unable to take care of the waste products, and as a result the system is affected by poisonous wastes which are produced by putrefaction in the intestines. A person in this condition is more liable to have rheumatism, gout, kidney and liver diseases than one in normal condition. A SHORT STUDY OF PROTEIN FOODS