Obesity main contributor to early puberty

The greater a young girl s body mass index, the earlier she enters puberty, according to Cincinnati Children’ s Hospital researchers as quoted by media reports Sunday. Puberty starts at an average age of 9.7 years old in white, and non Hispanic girls, according to the study, which is 4 months earlier than the statistics revealed in 1997. Researchers have tracked 1.200 girls for 7 years in San Francisco, New York, and Cincinnati since 2004 when they were only 6 to 8. It turns out that girls with higher body mass index enter puberty younger than those with lower BMI. Lead investigator Dr. Frank Biro suggested that a higher than average body mass index for a young girl may be the strongest predictor of early puberty. Environmental and physiological factors may also play a role but more specifics need to be confirmed. According to the researchers, girls who experience early puberty may have a greater risk for depression, obesity, hypertension, and certain cancers. Although the study suggested weight as a prime driver of early puberty, Biro said the question remains, "Why are they more obese?" Researchers are now looking for explanations other than increasing calorie consumption and less physical activity, such as exposure to chemicals in the environment that may trigger hormonal changes.