Starches as Fuel

The starches contain no nitrogen except a mere trace in the framework of the grains or roots they grow in. They burn very clean; that is, almost the whole of them is turned into carbon dioxid gas and water.

Virtues and Drawbacks of Meats

Taken all together, the proteins, or meats, are the most nutritious and wholesome single class of foods. Their chief drawback is their expense, which, in proportion to their fuel value, is greater than that of the starches. Then, on account of their attractiveness, they may be eaten at times in too large amounts. They are also somewhat more difficult to keep and preserve than are either the starches or the fats. The old idea that, when burned up in the body, they give rise to waste products, which are either more poisonous or more difficult to get rid of than those of vegetable foods, is now regarded as having no sufficient foundation. Neither is the common belief that meats cause gout well founded.

Protein in Vegetables

Several vegetable substances contain considerable amounts of protein. One of these has already been mentioned,—the gluten or sticky part of bread,—and this is what has given wheat its well-deserved reputation as the best of all grains out of which to make flour for human food.

Soups and Broths

Soups, broths, and beef teas are water in which meats, bones, and other scraps have been boiled. They are about ninety-eight per cent water, and contain nothing of the meat or bones except some of their flavor, and a little gelatin.