OBESITY is an excessive accumulation of fat iii various parts of the body. It is not possible to define the boundary beyond which the fat in the body can be called exceasaive, for persons possessing it in the most varied degrees enjoy equally good health, and the same person may at different times poeseas more or less without any injury to his comfort. According to the calculations of Dr. Lankester (' Guido to the Food Collection,' South Kensington 3luseum) a human body weighing 154 pounds contains 12 pounds of fat. This quantity may be exceeded to a very large extent without producing obesity.
An excessive development of the adipose tissue may take place at any period of life. It is not uncommon in children ; is far more rare in youth and in the early periods of manhood ; and is most common after the ago of 40, at which time an increase in the quantity of fat is observed in perhaps the majority of persons.
The chief accumulations of fat take place beneath the muscles, in the omentum and mesentery, about the heart, on the chest, and under the chin. In all those parts a certain quantity of fat naturally exists, and here therefore its amount is merely increased ; but in canes of excessive obesity, it accumulates in situations whore before there was none, as among the minute fibres of the muscles, even of the heart, and in various other tissues.
The accumulation of fat in the body produces a variety of effects. It is generally accompanied with an indisposition to exertion, and this at last ao far prevents the growth of muscular tissue that stout persons become exceedingly feeble. This in also true of homes and oxen, which lose their capacity to labour as they become fat. Another evil attendant upon fatness is that the heart being taxed in proportion to the increased size of the body, becomes enfeebled, and leenl con gestions and irregularities of the circulation arc frequently the result. A proper expansion of the chest, and a free action of the abdominal muscles aye also prevented, which lead to shortness of breath on slight exertion. Although persons may be stout and live to a good old ago, yet their path is beset with danger, and their chances of life aro not so great as amongst persons with a normal ',quantity of adipose tissue.
The causes of obesity are both natural and acquired. It is wel known that among domesticated animals some have a greater tendency to accumulate fat than others, and such breeds are kept u] for the purpose. In the same way there are human beings win exhibit the same tendency, and in the ease of certain individuals the most persevering measures fail to reduce their weight. On what thi tendency depends it is difficult to say exactly, but there is reason t4 believe that it depends upon the food in the early stages of digestior - being converted into fat, which getting into, the blood is deposited is the adipose tissue by a kind of excretory process. In such individual the starch and sugar of the food appear to be more readily convertible into fat than in others. But whilst this tendency may naturally exist it can be greatly increased by diet. There can be no doubt that the
class of foods called carbonaceous,—starch, sugar, and fat—when taker in larger quantities than are required to maintain the heat of the body, are employed in developing the adipose tissue. Experiments or the feeding of animals have shown that in proportion as these sub stances are employed in the food do they become fat. Alcoholi( beverages, when not taken to such an excess as to produce mon disastrous results, have a tendency to produce fatness. They act in the first place by stimulating the digestive process, and in the next by preventing that action of the oxygen of the air on the blood and tissue, by which the carbonaceous foods are oxygenated and carried off it the form of carbonic acid. Sedentary and indolent habits also have e tendency to produce fatness. As it is by active exertion that the oxygen of the atmosphere is introduced to the tissues of the body, and they are changed and carried away, so if this process be prevented by indolence, the tissues go on developing, and this is frequently the cam with the adipose tissue. Heat has also a tendency to develops obesity Living in warm rooms, or in a warm climate, other things being equal, has a' tendency to produce fatness.
1Vhilat obesity is exposed to dangers of its own, a precipitate anxiety to keep it down or prevent it is most earnestly to be deprecated. The practice of taking vinegar to prevent obesity is attended with great danger, as it acts by destroying the digestive power of the stomach. Per sons also frequently put themselves on a abort diet, and without not only fat-forming matters but also flesh-forming matters in their food. In this way the heart soon breaks down for want of nourishment, and death occurs in a variety of ways from want of power in the central organ of the circulation. The entering also at once upon a system of hard exercise and short sleep is frequently attended with the death of the patient. The great object of treatment should be the gradual reduc tion of the fat, whilst the muscular power, especially of the heart., should be maintained. One of the most important things to be attended to is the nature of the diet. The amylaceous, saccharine, oleaginous, and alcoholic parts of the diet should be diminished. No butter et breakfast, no bread at dinner, and one glass of wine a day is a good receipt for a healthy fat man who has been in the habit of living indiscriminately. Hard biscuits may also be advaotageonsly sub stituted for bread. Regular exercise should be taken, never excessive. Sawing, digging, walking and mountaineering according to the weight and strength of the patient are all good. Generally the obese are infirm of will, and this bodily state is perhaps connected with their mental condition, and of all patients they seem least able to make up their minds to the necessary discipline for their cure. If the per suasion implied in the sentence of " six months at the treadmill " could in any manner be applied in their case, it would undoubtedly be the most effectual remedy.