more of women, is by no means constant, but, as a rule, when we are
holding our own with that share of stored-up fat which belongs to the
individual we are usually in a condition of nutritive prosperity, and
when after any strain or trial which has lessened weight we are slowly
repairing mischief and laying by fat we are equally in a state of
health. The loss of fat which is not due to change of diet or to
exercise, especially its rapid or steady loss, nearly always goes along
with conditions which impoverish the blood, and, on the other hand, the
gain of fat up to a certain point seems to go hand in hand with a rise
in all other essentials of health, and notably with an improvement in
the color and amount of the red corpuscles.

The quantity of fat which is healthy for the individual varies with the
sex, the climate, the habits, the season, the time of life, the race,
and the breed. Quetelet[3] has shown that before puberty the weight of
the male is for equal ages above that of the female, but that towards
puberty the proportional weight of the female, due chiefly to gain in
fat, increases, so that at twelve the two sexes are alike in this
respect. During the child-bearing time there is an absolute lessening on
the part of the female, but after this time the weight of the woman
increases, and the maximum is attained at about the age of fifty.

Dr. Henry I. Bowditch[4] reaches somewhat similar conclusions, and shows
from much more numerous measurements of Boston children that growing
boys are heavier in proportion to their height than girls until they
reach fifty-eight inches, which is attained about the fourteenth year.
Then the girl passes the boy in weight, which Dr. Bowditch thinks is due
to the accumulation of adipose tissue at puberty. After two or three
years more the male again acquires and retains superiority in weight and
height.