All healthy people should possess a certain quantity of fat, but the proportion must necessarily vary, the average being from 18 to 22 per cent. of the body-weight in an adult man, and from 25 to 28 per cent. of the body-weight in an adult woman. It is a comparatively easy matter to effect the dissipation of fat in anybody, provided the proper conditions are observed, but it is a much more difficult matter to effect an increase in the adipose tissue and so produce a gain of weight. But if those suffering from the consequences of chronic exhaustion are to derive any real lasting benefit, they must be coaxed or compelled to make a substantial increase in their weight. Many people are perfectly healthy with a minimum of subcutaneous fat, but neurasthenics, especially when the seat of their trouble is in the alimentary canal, do not make progress nor maintain their improvement unless a certain amount of reserve adipose tissue be accumulated.

Fat can be deposited in the tissues from the consumption of any of the three chief classes of food-stuffs, and there is little doubt that the fatty globules deposited in the body are capable of contributing in some way, directly or indirectly, to the formation of muscular tissue. It may be that these act only in the capacity of protein sparers, but in any case in this lies our chief hope in the regeneration of such patients, for the renewal and strengthening of their muscular tissues is an absolute necessity. The chief protein tissues are blood and muscle, and the amounts of blood and protoplasm as represented in the composition of muscle have a definite relation to each other, in health the latter depending directly on the former. It is very difficult to fix a standard of muscular bulk or fitness, but there can be no question that an individual only attains to the best health when his muscles are developed to their full physiological limit.

Our chief aim, therefore, in all cases of nervous exhaustion, is so to augment the supply of nutriment and diminish the expenditure of energy that a reconstruction of the tissues - particularly those of the involuntary muscles, like the alimentary canal, heart, and minute arterioles throughout the body - may be effected. The important element in such a case is of course forced feeding, and the quantity of food required to accomplish our object will vary with the weight of the individual. It is therefore requisite in the first place to estimate the maintenance diet, and the amount ingested above this quantity is surplus of food, which von Noorden has calculated will increase the weight from 600 to 1,000 grams weekly for a daily addition of 500 to 800 calories.