A new study finds that young girls with a higher body mass index tend to have an earlier onset of puberty.
The researchers, who published a report in the journal Pediatrics, followed over 1,200 girls for seven years. They reported that African American girls began developing breasts before the age of nine, while white girls on average were beginning puberty around age nine-and-a-half.
Dr. Sara Lappe did not take part in the study, but is a pediatrician at the Cleveland Clinic. She said, "They found that girls that are above the 85th percentile considered overweight were found to develop breasts earlier than they were 10 to 15 years ago."
According to Lappe, completing puberty earlier in life can put girls at a long-term risk for diseases including breast cancer.
Although the findings implicate obesity as a "prime driver," the researchers report that early puberty can be attributed to many other factors as well, including: low fiber intake; preschool high-meat diets; dairy products; high-stress families; absent fathers; hormone-laced hair products; activity level; and geographical location.