As the body is essentially composed of the alimentary principles, and as the total carbohydrate-content of the body in the shape of glycogen falls decidedly short of 400 grams, it is manifest that the moment this is utilised - and this is not a difficult matter - the organism must fall back on the protein and fat for its energy production. The combustion of these substances, with the excretion of their end-products in addition to the mineral salts and water, must necessarily be accompanied by a loss of weight. On the tenth day of his fast Cetti had lost 6.35 kilos, equal to 11.14 per cent, of his original weight, and on the thirtieth day Succi had lost 14.3 kilos, equal to 22.7 per cent, of his weight just before the fast began. Although adipose tissue is easily and rapidly burned up, the fat, in the form of lecithin - a definite component part of the protoplasm - resists decomposition to a large extent. The loss of weight for the first week is from 800 to 1,000 grams daily, equal to from 1 to 1 1/2 per cent. of the body-weight.

The disintegration of protein is more regular, although even in this case there is a differentiation between the various forms of protein, especially the nuclein of the cell resisting longer than the rest of the bioplasm. During the first few days the phosphorus-free albumins are decomposed, and thereafter the phosphorus-containing albumins are attacked. The loss of weight is at first more rapid than at a later date, and is never relatively great when small quantities of water are being consumed. In a short fast, indeed, the body-weight is wholly without significance, because as much as 100 grams of fat, equal to 930 calories, may be withdrawn and are capable of being replaced by an equal quantity of water. It is important to note that the loss of body-weight is greater when protein is being drawn upon for energy than when this is derived from fat, for 1 gram of body fat always produces 9.3 calories, whereas 1 gram of flesh only represents .8 calorie by its combustion.

Estimation of the results of a fast by observation of the body-weight is, therefore, distinctly misleading and elusive. Any gain in weight during a fast can only be accounted for by the absorption of water, and it is therefore futile to suggest that death occurs when a definite proportion, say one-third or one-half, of the body-weight is lost. Rubner calculated that as much as 70 per cent. of the potential energy of the body tissues may be lost, this being divided somewhat as follows: - of the fatty tissues, 95 per cent. disappear; of the muscles, glands, and blood, from 40 to 60 per cent. may be dissipated; and of the bones about 15 per cent. is lost, while the nervous system only loses from 1 to 2 per cent. of its weight.

In no known fast of any duration has there ever been a gain of weight, and scientists all agree that the loss of weight is fairly uniform, although a little higher at the beginning than towards the close, as might be expected from the gradual decline of the functional activity of the organs. In cases where daily injections of water to a considerable extent are administered, on the mistaken conception that thereby the excretion of deposited morbid material will be hastened, a fairly large proportion may be absorbed, and this would account for an apparent diminution in the average loss of weight. It must be repeated with emphasis that in all cases the body lives on its own tissues, and so long as adipose tissue is present this is used in preference to the vital tissue of the body. In a case reported by Rubner the daily nitrogen output was 1.67 grams for the first three days, 1.46 grams from the fourth to the sixth day, and 3.21 grams from the sixth to the eighth day, while the fat burned on the second day was 10.3 grams, the same on the fourth day, and only 2.4 grams on the eighth.

On the average about 12 ounces (350 grams) of weight per day are lost during a prolonged fast of over thirty days' duration, and this is valuable tissue material extracted from the healthy tissues of the body. It is an absurd fallacy to suggest that it is a clearing away of excrementitious material. At the very outside muscle contains not more than 2 per cent. of waste products, so that the average man's body contains in all no more than 2 pounds of waste material. This weight may very easily be lost during the first twenty-four hours of a fast, and any further loss of weight during its progress can only be ascribed to the consumption of the bodily tissues themselves. In other words, the subject of the experiment is for the time being a cannibal, and this explains many phenomena that would otherwise be unaccountable.

Lusk quotes Kumagawa's results, showing the percentage weights of the different organs in the fat-free organism of a dog before and after a twenty.four.day fast, and also the percentage loss of the fat-free organ in starvation: -

Loss In Weight Of Different Organs During Starvation