Most American families eat too much protein food, such as meat and eggs. Excess of protein probably leads to degeneration of tissues, and plays a part in causing the degenerative diseases already mentioned. Habit is important here as in other ways of living, but cereals and vegetables should in large measure make up the diet of sedentary persons and indeed of everyone in warm weather.
The amount of food required in 24 hours depends on many factors: age, height, weight, occupation, season, and habit. Underweight and
overweight are both abnormal conditions; probably the latter is the more easily remedied. Both require the advice of a physician. Rapid reduction of weight involves certain dangers, especially for persons with weak hearts.
Food may cause sickness either because it is in itself harmful, or because it carries disease germs. Meat from diseased animals should be destroyed before it reaches the market, but bacterial activities in food originally wholesome may form in it poisonous substances.
The chief diseases known to be carried by food, water, or milk are typhoid fever, paratyphoid, dysentery and other diarrhœal diseases, scarlet fever, diphtheria, septic sore throat, and tuberculosis. The sole problem here is to keep human and animal excretions out of food, water, and milk. Since thorough cooking kills disease germs, danger arises chiefly from raw foods. All fruits and vegetables eaten raw should first be thoroughly washed.
Water is essential to health. At least three pints should be taken daily, the amount varying somewhat according to diet, exercise, temperature, and so forth. Most persons drink too little water.
Cities and towns should of course have public supplies of pure water. Contamination of water,
when it occurs, is caused chiefly by sewage from cesspools, privies, and drains. All well or spring water must be constantly watched and Boards of Health are always ready to examine samples of water and to report whether it is safe to drink. At the present time a porcelain filter is the only satisfactory kind for a household, but many domestic filters are so badly cared for that in actual practice they are worse than none. Danger from a filter containing an accumulation of impurities is greater than the danger from most ordinary water supplies. Boiling water for ten minutes kills all pathogenic germs, but this method is inconvenient on a large scale and is not practical for continued family use.
Every effort should be made to insure a regular supply of pure water in every house. It is not satisfactory to have two kinds, one for drinking and one for other purposes, since mistakes are sure to be made, especially by children. Some families who use only bottled or filtered water for drinking purposes habitually run the risk involved in using impure water from the tap for cleaning the teeth.
Freezing destroys most germs, but ice is not necessarily free from bacterial life, and should be used in drinking water only when known to be free from impurities. Neither does freezing milk