Puberty at 10: How It Affects Girls

June 18, 2012— -- By the time she was in third grade, Becki Holmes said she needed to shave her underarms and legs because her classmates taunted her for the body hair that resembled that of a teenager's. When she was 8, she started wearing sports bras.

She got her first period at 9 years old.

"My mom gave me a shoebox full of feminine products to the school nurse to keep in the nurse's bathroom so that I wouldn't need to carry it with me," said Holmes, now 20, of Manchester, N.H.

By the time she was 10, Holmes was diagnosed with depression.

"I have always been bigger than other kids," continued Holmes. "That led to the bullying which led to the comfort eating."

Holmes soon became overweight as a result of the emotional overeating.

"My home was always broken," she continued. "My parents finally got divorced about five years ago but the fighting was always there. Hearing all of the yelling and insults definitely contributed to my emotional duress I experienced in my childhood."

Now, experts say a childhood like Holmes' may be the perfect storm to trigger early puberty in girls. The breakdown of the family unit may cause a domino effect in young girls, which can prompt overeating, obesity and potential early puberty, according to a scientific meeting intended to review a myriad of studies based on girls and puberty.

Researchers converged last week at the Cheltenham Science Festival in England to answer questions related to early puberty.

"Speakers agreed that childhood obesity, or more specifically, increased body fat content, is the single most important factor that we know provides part of the explanation for advance in puberty (particularly in girls) in most countries," Richard Sharpe, professor in the Centre for Reproductive Health at the University of Edinburgh, wrote in an email to ABCNews.com.

But, there are clearly other factors that play into early puberty, as well. Societal factors, such as adoption or absence of a biological factor, are associated with an increased risk of early puberty. Sharpe, who was a key speaker at the meeting, said he hypothesizes this may be in part due to an increased stress response in the body, which can "increase androgens that are then converted to estrogen in the breast and stimulate breast development."

Obesity among children continues to grow in the U.S., with about 17 percent, or 12.5 million, children and teens are obese, according to the Centers for Disease Control and Prevention. Since 1980, obesity among the youth population has nearly tripled. One in seven low-income pre-school children are obese.

A study in the journal Pediatrics first documented the younger ages age in 1997. The study showed that the average age of breast development and pubic hair was 9.7 years old for white girls and 8.1 for black girls.

A Pediatrics study published in 13 years later found that 25 percent of black girls, 15 percent of Hispanic girls and 10 percent of white girls were hitting the onset of puberty at age 7.

"I was bullied relentlessly by my peers, male and female, and I had no friends," Holmes said. "I was the weirdo that no kid wanted to play with because I was bigger. Somewhere around fifth or sixth grade, boys started to realize what breasts were and that added to their ammunition of teasing. In sixth grade, I had moved up into middle school, where the other kids were started to go into puberty normally.