"The average age of puberty is getting lower due to improved nutrition (and possibly excess calorie consumption)."
More likely caused by the hormones fed to our meat supply. One day my cousin was talking about her 4 daughers, none of whom have breasts. If you put them all together, you might come out with one pancake. I told her to stop feeding them home grown meat and start buying it at the supermarket. (just wanted to insert a little funny, here).
But the hormones in the meat is true.
I've heard the hormone in meat supply claim before, but I don't necessarily believe that is true.
One, the average age had already begun to drop long before the use of "hormones" and two, the use of "hormones" in growing meat animals isn't happening on a widespread basis. It is banned in chicken and pork and tightly controlled in beef.
I'm afraid this is a popular arguement of the eco-nazis but as usual it is based on fear, bad science and a deliberate misunderstanding of the truth.
http://www.useu.be/issues/BeefPrimer022699.html It is also European propaganda to keep our meat out of their markets. Ours is better (and cheaper) and we would kick their butts on a level playing field.