Two new studies on childhood and adolescent obesity have shed further light on the potentially far-ranging public health consequences of the United States’ weight troubles.
One study, funded by the National Institute of Environmental Health Sciences and published in the journal Pediatrics, suggests that obesity may contribute to girls entering puberty earlier than ever before.
The other, a survey of teens who had sought weight loss surgery, indicates that obese adolescents experience several health conditions that have previously only been seen in adults. The reserach was funded by the National Institutes of Health and published in JAMA Pediatrics.
The Environmental Health Science study appears to show that girls are entering puberty at younger and younger ages, which could put them at risk of a host of physical and mental health issues, including breast and ovarian cancer, high blood pressure and depression.
The research, which is based on a group of 1,200 girls in New York, the San Francisco Bay area and the greater Cincinnati area, is part of the government funded Breast Cancer and the Environment Research Program.
The study also found a disparity in maturation based on race.
Breast development began in white, non-Hispanic girls, at a median age of 9.7 years, earlier than previously reported. Black girls continue to experience breast development earlier than white girls, at a median age of 8.8 years. The median age for Hispanic girls in the study was 9.3 years and 9.7 years for Asian girls.
But the study suggested that a higher body mass index, or ratio of height and weight, was "the strongest predictor" of early breast development across all races in the study.
"The obesity epidemic appears to be a prime driver in the decrease in age at onset of breast development in contemporary girls," said the research led by Frank Biro at Cincinnati Children's Hospital.
The girls enrolled in the study beginning in 2004 when they were between the ages of six to eight, and their development was tracked for multiple years.
A trend toward earlier puberty has been noted in past international studies as well.
Research from Denmark published in 2009 showed that girls were experiencing breast development nearly a year earlier than those born 15 to 16 years before.
The study published in JAMA Pediatrics, also released Monday, showed other serious health impacts that can be linked to the rising obesity among young Americans.
It found that U.S. teens seeking weight-loss surgery have a startling number of health problems that used to be seen only in adults.
Half the teens had at least four major illnesses linked to their excess weight. Three out of four had cholesterol problems; almost half had high blood pressure or joint pain; and many had diseased livers or kidneys.
The study involved 242 teens who had surgery at five U.S. centers from 2007 through 2011.
The study also suggested that gastric bypass surgery might be the most effective option for severely obese teens.
An earlier study showed that obesity rates among children have fallen slightly in recent years.
Al Jazeera and wire services