OBESITY - THE INFLUENCE OF AGE.
It is known that the normal fat formation in man is influenced by the age, in connection with which the mode of nutrition, rest, and slight muscular activity are of decisive importance. The pathologi cally increased fat formation likewise depends materially upon the age and the conditions of life appropriate to it.
In infancy the fat production is maintained in especial manner by the milk diet as well as by the absence of great muscular ac tivity, which favors the formation of fat; and nurslings who are arti ficially fed with farinaceous substances exhibit not rarely quite an extraordinary increase of adipose tissue. In adolescence, in which much nutritive material is used for building up the organism, and in advanced age which presents a continual consumption and ret rograde metabolism in all the tissues, there is generally a lack of all the conditions which permit of an abnormal accumulation of fat in the body.
The periods that are most favorable for the development of cor pulence and obesity are in men advanced middle age between the forti eth and fiftieth years, and in women the climacteric toward the end of the fourth decade of life, in which the ingestion of food and consump tion Of material are most frequently in a relation favorable to the utilization and accumulation of fat. Thus statistics prove that the greatest development of fat in the male sex occurs in the period be tween forty and fifty years, and that the least production of fat occurs between fifteen and twenty years. In the female sex, however, the development of fat about the time of puberty, between fifteen and twenty years of age, is far greater than in the male sex. Further
more the amount of fat development is nearly uniform in women during the decade between thirty and forty, and next to this during that between forty and fifty years, where the occurrence of puberty, the puerperium, and the climacteric favor the accumulation of fat (Kisch).
The age at which the congenital disposition to fat hyperplasia manifests itself has been already mentioned above. In general, opin ions vary greatly. Many observers agree that in such cases an ab normal development and accumulation of fat occur even in earliest infancy. The obesity of such children, according to Meckel, presents the character of morbid and premature development. As a rule, however, the early fat hyperplasia undergoes a diminution. The fat formation returns to the normal and increases again in later years, either after puberty or at the time of greatest vigor, but most fre quently in advanced age.
With the age of the individual, too, the location changes in which the excess of fat is deposited. This remarkable process seems to stand in a causal relation to growth. In embryos and the new-born the subcutaneous cellular tissue, the omentum, and the mesentery re main free from fat even when the deposit is great in other places. As long as the growth in height continues, but little fat is found in the internal organs, while during middle age large quantities are ac cumulated in the omentum, mesentery, pericardium, mediastinum, etc. In old age, on the other hand, the fat persists for a long time in the internal organs after that in the subcutaneous cellular tissue has largely disappeared.