Although recent reports suggest the childhood obesity epidemic in the US may have abated somewhat, a new study finds that the overall trend masks growing socioeconomic disparities, with teens in poorer families showing increased rates of obesity.
In August 2013, researchers reported how for the first time in 30 years, in all but one state of the US, obesity rates are holding steady.
Meanwhile, also in August 2013, the Centers for Disease Control and Prevention (CDC) reported that US child obesity rates are dropping.
Stable pattern masks widening gap
But Dr. Carl Frederick, of Harvard University in Cambridge, MA, and colleagues noticed a disturbing pattern underlying these apparently welcome trends, which they reported in a recent online issue of Proceedings of the National Academy of Sciences:
"[...] we document that the overall trend in youth obesity rates masks a significant and growing class gap between youth from upper and lower socioeconomic status (SES) backgrounds."
The researchers found an obesity rate class gap, in which obesity rates among teens from an upper socioeconomic group fell, while rates among teens from a lower socioeconomic group increased.
They found that up to 2002, obesity rates for all teenagers rose at the same rates, but after that, a class gap appeared, and got wider and wider, showing that while obesity has starting falling among teens of higher socioeconomic status, it has continued to rise among those of lower socioeconomic status.
The authors say their findings highlight a need for public health interventions to address disadvantaged adolescents who remain at risk. They should also look at how health information circulates among different socioeconomic groups, they add.
For their study, they examined changes in obesity by socioeconomic background among American youngsters aged between 12 and 17. They got their data from two nationally representative health surveys: the 1988-2010 National Health and Nutrition Examination Surveys (NHANES) and the 2003-2011 National Survey of Children's Health.
They describe what they found:
"Although the overall obesity prevalence stabilized, this trend masks a growing socioeconomic gradient: The prevalence of obesity among high-socioeconomic status adolescents has decreased in recent years, whereas the prevalence of obesity among their low-socioeconomic status peers has continued to increase."
Widening obesity gap between groups linked to lifestyle differences
The comprehensive data set allowed them to look at other possibly linked factors. They found for instance, there were also socioeconomic differences in levels of physical activity, and calorie intake, which they note "may have contributed to the growing obesity gradient."
They suggest doing more to promote healthy lifestyles among young people, especially in the lower socioeconomic groups, would not only help tackle the obesity epidemic among teenagers and reduce the burden of consequent chronic diseases, but would also reduce future health care costs and pave the way for an overall healthier nation.
Written by Catharine Paddock PhD