Instances of abnormal cravings for food are familiar to every one. They sometimes take the form merely of an inordinate desire for food which is in itself wholesome but which is poorly adapted to an existing diseased condition. Such desire is apt to come in the course of any protracted illness in which a very restricted diet has been maintained for weeks. It is largely psychic, and does not necessarily indicate an increased appetite. The dysenteric patient may long for ham or pickles or vegetables, or the very obese will beg for sweets, preserves, or farinaceous food.

In other cases the craving may be an indication of a positive want in the system, as when a scorbutic patient hungers for fresh fruit and vegetable acids.

In no disease is the craving for food of every kind more pronounced than in convalescence from typhoid fever. In this case the hunger can hardly be considered abnormal, for it is an expression of the need of wasted and exhausted tissue throughout the body for nutriment.

Patients usually find it most difficult to give up the class of foods which they well know does them most harm. The subject of flatulent dyspepsia longs for saccharine, and perhaps amylaceous or fatty foods - confectionery, pastry, and the like - and the diabetic sometimes has an inordinate craving for bread, which so far possesses him as to cause a resort to any subterfuge to obtain it.

In disordered mental conditions, hysteria, hypochondriasis, melancholia, and in the peculiar periods of puberty, pregnancy, and the menopause, cravings for wholly injurious articles may occur. Such patients have been known to eat chalk, or sour food, or consume large quantities of salt, sodium bicarbonate, etc.

With the exception of chronic alcoholism - if alcohol be regarded as a food as well as a stimulant - there is no distinct food "habit," in the sense that any particular food is likely to be long eaten to an injurious excess. Those articles of diet which are oftenest abused are condiments and confectionery.