The accumulation of fat in the body is a frequent condition after the age of forty. Those who have read the previous chapters will not be surprised to learn that this accumulation of fat is generally due to the intake of food being larger than is necessary for the requirements of the body. "Why, I am a very small eater, and yet I grow fat," is the indignant exclamation; for there is nothing people resent so much as being told that they eat too much. The inexorable fact, however, remains that if you grow fat, you either take too much food in bulk, or too much food of a certain kind, that is of a fattening kind. This excess may be every day exceedingly small, and yet in the course of a year, or a series of years, it results in transforming a once graceful figure into an unwieldy shape, and an active energetic person into one to whom movement and exercise are repugnant. Dr. Burney Yeo has shown in a very practical way how a large accumulation of fat may take place in a few years from a very small cause. He instances the case of a person who daily takes in excess of his wants half an ounce (about two lumps) of sugar. This sugar not being required and burnt off is converted into fat, and stored up in his body as such. This daily consumption of sugar, and this daily storage of fat, will result in one year in increasing the weight of a person eleven pounds, and in five years in raising it no less than four stones. From this example it is seen how in middle age, when metabolism is slow, a small excess of fattening foods will lead to obesity by imperceptible degrees. It rarely has the same effect in youth, when the body is able to consume and get rid of much larger quantities of food. There are, it is true, certain cases of obesity which are pathological instead of physiological; these are generally associated with anaemia, or with fatty degeneration of the heart, leading to imperfect oxidation in the tissues, or with hysteria. Such cases are not within the range of this work, and should be treated by the physician. Treatment. - In the treatment of ordinary obesity there are certain definite principles to be followed.

1. To oblige the body to feed for a while on itself, and to consume its own fat;

2. To prevent the re-accumulation of fat.

Both these conditions can be accomplished by diet.

Before commencing the dietetic treatment of obesity the patient should undergo a careful physical examination by a physician to ascertain if the organs, particularly the heart and kidneys, are sound. Some of the systems in vogue for reducing fat tax these organs severely, and if there are any signs of incompetency or disease of the heart or kidneys, the system adopted should be modified accordingly. It will be remembered, that when explaining the action of hydro-carbons and carbo-hydrates in the body it was stated that carbo-hydrates - i.e., starchy and sugar foods - are the substances out of which adipose tissue is manufactured; but that, as in the case of fattening pigs, the production of fat in the body is much more rapid if fatty foods are taken in combination with starchy foods. Thus it was shown that pigs fatten much more rapidly on meal and greasy pig-wash than on meal alone. From these facts we infer that the ordinary mixed diet of adults, consisting of meat, fat, and farinaceous foods, is, after the period of youth and activity is passed, liable to cause an excessive deposit of fat. The indication is, therefore, to cut off the farinaceous foods, and, according to some authorities, to cut off the fatty foods as well. It is not, however, sufficient to reduce the consumption of fatty and farinaceous foods; the intake of food, and more especially of fluid food, must be reduced generally. It is useless for the fat person to say: "I will not diet myself, I will take more exercise". If he increases exercise he will probably increase appetite, and consequently the intake of food. He must increase exercise and decrease the intake of food, being willing to suffer even for a time the pangs of hunger until the body learns to feed upon itself and habit has modified appetite.