In studying the dietaries of people in all times, it is very interesting to note that the use of composite foods is universal, and further, that these compounded foods are composed of the ingredients that form a dietetic balance. One of the simplest compositions that could be cited is bread and butter. A glance at the chemical composition of bread shows that, while it has a proportion of protein and of carbohydrate, fitting it for a complete food, it is short in fats. When one eats bread he craves fat of some kind with it, and so from time immemorial people have spread butter upon bread, or they have dipped it in beef fat, or have spread upon it rich gravies, in this way adding to bread the foodstuff that it most lacks. Pork and beans is another composite food in which the fat of the pork supplements the proteins and carbohydrates of the beans, making a close approach to a perfect food-balance. Macaroni and cheese is easily prepared, with milk and some added fat, perhaps butter, besides the butter-fat in the cheese, and is another good example of the composite food or "dish" in which there is a fairly perfect balance of proteins, fats, and carbohydrates. On such a dish as macaroni and cheese one could make a complete meal, satisfying every requirement of the body. In a milk custard we have eggs, milk, and sugar, forming a combination in which the proteins, fats, and carbohydrates are so balanced as to make the dish a perfect food. A whole meal could be made on such a dish and satisfy every requirement of the system.