Pubertal adipose tissue: is it necessary for normal sexual maturation? Evidence from the rat and human female.

The high percentage of fat (about 26-28%) in the mature human female may influence reproductive ability directly: 1) as an extragonadal source of estrogen; and 2) by influencing the direction of metabolism of estrogen to the most potent or least potent forms. The slow maturation of the hypothalamus and pituitary up to menarche, or first estrus, is accompanied by a slow maturation of the body, which changes not only in size but in the relative proportion of bone, muscle, and fat. Evidence is presented that a particular ratio of fat to lean mass is normally necessary for puberty and the maintenance of female reproductive ability in the human and rat. The synchronizing signals may be metabolic, relating food intake to core temperature and fat depots.