In a book of this character it wouldn't be amiss to say a few words on the effect of cooking on meats and vegetables. Will quote from the work of Friedenwald and Ruhrah on Diet :

"The effect of cooking on meat is to diminish its watery constituents, thus concentrating and rendering it more nutritious; by this process also the extractives, as well as some of the fats, are partly removed.

The chief loss in weight during boiling, sauteing, and pen broiling is due to water removed by the heat of the cooking. In the roasting of meats the chief loss is due to the removal of both water and fat. In pan broiling the losses which take place are very small as compared with the other methods of cooking. The longer time meat is cooked, and the higher temperature at which this is done, the greater the loss in water and fat, the larger pieces losing relatively less than the smaller ones.

The important object in the cooking of vegetables is to rupture the cellulose envelop and so to soften the contained starch-granules. Under the influence of heat and moisture the starch swells and bursts its envelop, forming a paste; this paste, in its turn, expands and ruptures the cellulose envelope; cooking, therefore, renders vegetable foods more easily digestible.

In the cooking of meats a certain portion of the ingredients are lost. Unlike meats, however, vegetables become more watery in cooking. In this condition they are more easily acted upon by the gastric secretion; on the other hand, the addition of water in cooking so increases their buk that the motor function of the stomach is apt to be overworked."

Dr. C. D. Jeffries.