Sorry, too busy to comment on this subject until today ...

I read in one of those supermarket-checkout-line womens' magazines that
a study indicated that precocious puberty is related to the percentage
of fat in the child's body.  In other words, as we pack our children
more and more with refined flours, sugar, soda pop, and french fries,
their percentage of body fat is higher at a younger age, setting off
puberty.  This would account for puberty in Japan coming earlier, also,
as they eat in a different pattern over there now than they did before
the War and so much Western influence and economic prosperity.  We know
they are taller now, so they may be "fatter" also.

Perhaps walking to school, cutting firewood, and doing farm chores kept
children from putting on fat at this rate a generation or two or three
ago.

Patty