Proteins are found in almost all types of food, but some have far more than others. Richest sources of protein are milk, eggs, cheese, meat, fish, whole-grain cereals, peas, beans, lentils, peanuts, and soybeans. Because most kinds of meat are rather expensive, many families may find them beyond their means. For various reasons, other families may prefer a vegetarian diet. Fortunately, a combination of vegetables and cereals will usually supply all the proteins any person may actually need.

Milk and dairy products are among the best sources of protein. Generally speaking, they are easily digested and absorbed by the body. Milk contains a complete protein, and at the same phosphorus in just the right proportions for growing children and for nursing mothers. But even with so good a food as milk, we must still add a word of caution. Milk easily contaminated by disease-carrying germs, both during the milking process and also while being stored. Therefore, all milk should be boiled or pasteurized before being used. Boiling for only a few minutes will quickly kill all harmful germs.

Meat is another good source of protein. It is also rich in iron, phosphorus, and some of the B complex vitamins. But all animal meats contain certain waste materials which must be eliminated by the kidneys. This means extra work for the body, as well as trouble for those whose kidneys may have been damaged by disease. There are many good arguments for living on a non-meat diet. However, vegetarians should be sure to take enough protein in other ways, such as in peas, beans, whole-grain cereals, and milk products.