Heavier girls tend to reach puberty early

[snopes]

Pediatric experts had noticed that girls appeared to be developing breasts (the first outward sign of puberty) at earlier ages — and that they tended to gain weight around puberty. But no one knew which came first: earlier development or weight gain. By tracking girls' weights from early ages, researchers have found that the extra pounds come first.

http://www.latimes.com/features/heal...,1,15179.story

[medtchva]

The fact that fat tissue produces estrogen probably contributes.

[Banrion]

The weight may come first, but isn't weight gain part of female puberty? So maybe the whole problem lies in the fact that they are calling development of the breasts the first sign of puberty, when really weight gain is the first sign which later leads to development of breasts.

I'm not an expert, but I definatly had MAJOR weight gain just before I hit puberty, and after 4 months of excrutiating pain, and growing 7 inches, I was back down to a normal weight. I really was one of those "Over the summer" girls.

[snopes]

Increasingly — though the science is still far from definitive and the precise number of such cases is highly speculative — some physicians worry that children are at higher risk of early puberty as a result of the increasing prevalence of certain drugs, cosmetics and environmental contaminants, called “endocrine disruptors,” that can cause breast growth, pubic hair development and other symptoms of puberty.

Most commonly, outbreaks of puberty in children are traced to accidental drug exposures from products that are used incorrectly.

http://www.nytimes.com/2006/10/17/sc...17puberty.html