It is evident that milk with its high protein content is a food par excellence for the growing organism or for the invalid convalescing from wasting disease. It contains too large an amount of protein for a normal adult. A mixture of milk, toast, and cream (creamed milk-toast) may produce a modified milk diet of proper value and easy digestibility. An exclusive milk diet contains too little iron for the needs of a normal adult.

Moritz2 recommends milk alone in treatment of obesity, in quantities varying between 1.5 and 2.5 liters daily. The normal weight in kilograms of the individual is calculated from his height, and each kilogram of such weight is provided with 16 to 17 calories in the diet, an amount which is contained in 25 c.c. of milk. Should the normal weight be 80 kilograms, 2000 grams of milk are administered daily in five portions. Such treatment brings about a considerable loss in body weight, and, although some body nitrogen is lost, a state of weakness does not ensue.

Rubner finds that 1500 grams of good white bread containing 104.4 grams of protein will maintain a working man in nitrogenous and calorific equilibrium.

1 Thomas: "Archiv fur Physiologie," 1909, p. 417.

2 Moritz: "Munchener medizinische Wochenschrift," 1908, lv, 1569.

Thomas1 took on three successive days an average of 2760 grams of fresh bananas which were not completely ripe, and to this he added 300 grams of sugar. This gave a total intake of 4.32 grams of nitrogen and 2741 calories daily. Although a preliminary diet of starch and sugar had reduced the urinary nitrogen to 3 grams at the beginning of the experiment, nitrogen equilibrium could not be obtained when the above noted amount of bananas was ingested. The unripened starch of the banana is eliminated in the feces. Ripe banana in which almost all the starch has been converted into glucose is very completely digestible. Whereas five parts of potato protein may replace four of body protein in establishing nitrogen equilibrium, the protein of banana is not so efficient. Yet in tropical countries, such as the sea-coast of East Africa, the Congo, and in the Pacific Islands, during the six months of the rainy season (in which the banana is ripe), it furnishes almost the exclusive diet of the natives. It is preferred to potatoes because it can be obtained almost without labor. Banana flour is also prepared in these localities by drying unripe bananas in the sun.

If water be taken when the stomach is empty it quickly passes through the pylorus into the intestine. Taken with food, however, its exit from the stomach is considerably delayed; the delay accounts for some of the pleasure of afternoon tea when taken with toast. Beer remains in the stomach longer than water, and this may be due to the extractive substances or to a narcotizing effect upon the musculature of the stomach.2

Atwater and Benedict3 have conclusively shown that alcohol may be used in the economy in place of isodynamic quantities of carbohydrates and fats. The following table shows the average of experiments on a resting individual which lasted twenty-three days:

1 Thomas: "Archiv fur Physiologie," i9i9, Suppl., p. 29.

2 Grobbels: "Zeitschrift fur physiologische Chemie," 1914, lxxxix, 1.

3 Atwater and Benedict: "Memoirs of the National Academy of Sciences," Washington, 1902, viii, 231.

Influence Of Alcohol On Metabolism

Atwater and Benedict employed diets containing about 2500 calories for a man at rest and 3500 for a man at work. During the alcohol days 500 of the calories were supplied in 72 grams of alcohol, or about what is contained in a bottle of claret. The metabolism of the individual as expressed in calories was unchanged by the addition of alcohol to the diet. The alcohol was given in six small doses and 98 per cent, was burned by the organism.

On the ordinary diet 33.7 grams of fat were daily added to the body, and on the alcohol days 34.1 grams. These very valuable observations make it evident that alcohol is not a direct cause of obesity. If, however, a young man having acquired certain dietary habits at home continues the same diet at college and begins to drink "in moderation" besides, his increasing rotundity as he returns on his vacations can be readily explained by the sparing influence of alcohol upon the fat in his diet.

A liter of German beer contains 3 to 4 per cent, of alcohol and 5 to 6 per cent, extractives. It yields 450 calories to the body, only half being derived from alcohol, the rest from the dextrin and protein-like extractives. Here is a material whose "fattening" properties may be very highly considered.

It is reported that alcohol is present in normal human blood to the extent of 3 parts in 100,000. When alcohol is drunk it passes into the blood as such, and as much as 2 parts in 1000 has been found in the blood of a drunken man by Schweisheimer.1 According to this author, the intensity of the drunkenness depends on the concentration of alcohol in the blood. A maximum concentration is reached about an hour and a half to two hours after drinking and may remain high for five hours. Those who are accustomed to alcohol oxidize it all in seven and a half hours, whereas those who have been abstainers require twice that time.

It is interesting that although alcohol ingestion reduces the respiratory quotient after it has been given, it has never been found to reduce it to such an extent as to indicate that it is, the main source of the energy supply of the body.

An experiment by Durig2 showed that after giving 30 grams of fructose to a man every hour the respiratory quotient rose to unity; but if 30 c.c. of alcohol were given about the same time the respiratory quotient was depressed to about 0.80. Alcohol was, therefore, in large measure oxidized instead of sugar, but the respiratory quotient did not approximate 0.67, the quotient for alcohol itself, as would have been the case if the source of energy had been exclusively alcohol (see p. 298). These authors find no summation of dynamic effect when alcohol and carbohydrate are oxidized together (see p. 298).