As will be noticed, the animal foods contain the most protein and
fats, while the vegetable foods are rich in carbohydrates. A pound of
cheese may have 0.28 pound of protein, as much as a man at ordinary
work needs for a day's sustenance, while a pound of milk would have
only 0.04, and a pound of potatoes 0.02 pound of protein. The
materials which have the most fats and carbohydrates have the highest
fuel value. The fuel value of a pound of fat pork may reach 2.995
calories, while that of a pound of salt codfish would be only .315
calories. On the other hand, the nutritive material of the codfish
would consist almost entirely of protein, while the pork contains very
little. Among the vegetable foods, peas and beans have a high
proportion of protein. Oatmeal contains a large proportion also.
Potatoes are low in fuel value as well as in protein, because they are
three-fourths water. For the same reason milk, which is seven-eights
water, ranks low in respect to both protein and fuel value, hence the
reason why it is not so valuable as food for an adult as many of the
other food materials.

These few illustrations will help to show the need of an intelligent
idea of food values before attempting to purchase the supplies for
family use. As one-half a laboring man's income goes towards
providing food, it must follow that such knowledge will help the
housewife very materially in securing the best results from the amount
expended.

The _average daily diet_ of an adult should contain (Church):--

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NUTRIENTS. | IN 100 PARTS. | EACH 24 HOURS.