Meats contain, in common with vegetables, protein, fat, mineral matter, and water. They lack carbohydrates, the chief constituent of starchy vegetables. Meats contain more fat and protein than vegetables. It is for its protein and fat that meat has nutritive significance in human diet.

In vegetables, carbohydrates were found to include starch, sugar, cellulose. The action of any vegetable in the human system depends upon which of these forms of carbohydrates is present, or present in largest quantity.

Protein also is complex. Albumen, gelatin, nitrogenous extractives, are present in protein. Though these are all nitrogenous, they are differently composed and serve the body differently. Albumen builds tissue; gelatin spares tissue, but does not build it; extractives do neither - they stimulate. They have little, if any, nutritive value. By stimulating, however, they cause a secretion of digestive juices, which promotes digestion, hence nutrition, when the stimulation is not excessive. The flavor of meat due to extractives increases palata-bility. Extracts of meat contain mainly extractives.

Albumen is coagulated when meat is cooked. In boiling it rises on the water as brown particles. These are highly nutritious, therefore should not be skimmed off. The solidifying of the liquid in which meat has been boiled is due to the gelatin. When this is present in the diet it is used by the body and thus protects body-tissues. The body would consume itself in living if deprived of all protein food. Gelatin is a sparer of tissue instead of a builder. It is called a tissue-sparer. Veal is especially rich in gelatin.

When would you choose mutton in preference to beef? Why? When not? Why? In what respects does pork differ from beef and mutton? Compare young and old animals; young and old vegetables.