It is probable that, in prehistoric times, the food of man consisted of fruits, nuts, raw meats, and fish. Such is the diet of some primitive tribes to-day. Cooking in some form is, however, used by most known tribes.

The most northern Eskimos live almost exclusively upon meat rich in fat and oil which constitutes an important element of their diet and helps to balance it. Once in a while they obtain lichens from the stomach of the reindeer and the flower of the arctic poppy and the so-called scurvy grass are equally rare articles of food with them. They eat at irregular times and when it is possible.

Indians and uncivilized people in the temperate and tropic zones have a more varied diet. Fruits, nuts, some wild vegetables, fish, wild fowl, and other game supply their wants. In the tropics, where fruit is abundant at all seasons, it constitutes a large and often the main part of their food.

The diet of savages is governed by what is supplied by the country in which they live. The same statement, with a slight modification, can be made of civilized races, for they live chiefly upon what their country can be made to produce. Recently, however, since cold storage transportation has been made cheap and efficient, there has been effected an interchange of fresh commodities between the peoples of different lands and climates, thus no longer leaving them wholly dependent upon the soil on which they live.