People have known for a long time that fruit is an important part of a healthy diet. Here’s what it said in a hundred-year-old cookbook:
Fruit Essential in the Daily Diet
Fruit is really indispensable in a well regulated diet. Formerly it was considered an accessory, rather than an essential food, and was eaten mainly for its flavor and refreshing qualities. The food value of most fruits is not high, but the mineral salts they contain are necessary to good health. A person who eats quantities of fruit is usually in excellent health, and has a clear complexion, due to the body regulating qualities of the various mineral salts and organic acids contained in fruit. These organic acids import an agreeable acid flavor and help to keep the blood in good condition. Most fruits contain a large proportion of water, also of value in the diet.
If the family does not care for fruits between meals, which is really one the best times to eat them, see that fruit in some form is furnished for at least one meal a day, for it is a necessary part of the daily diet. Do not consider fruit an extravagance and accessory. If we are to have healthy bodies, fruit is an essential, and although its actual food value, if fresh, is not high, its health-giving properties are a necessity.
Mrs. DeGraf’s Cook Book (1922)