Childhood and teen obesity rates seem to be levelling in the U.S. overall but poorer youth are still at risk, say researchers exploring a class divide. 
 
Between 1988 and 2011, two national surveys in the U.S. suggested the national prevalence of obesity among Americans aged 12 to 17 increased until 2004 with no changes up to 2010.  But a new analysis of the data indicates differences depending on family income and parental education. 

Ont Obese Kids

Average energy intake has fallen more among children from wealthy, educated homes than other children, researchers found. (Chris Young/Canadian Press)

"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 backgrounds," Robert Putnam of Harvard University in Cambridge, Mass., and his co-authors concluded in Monday's online issue of the Proceedings of the of the National Academy of Sciences. 
 
"These results underscore the need to target public health interventions to disadvantaged youth who remain at risk." 
 
The good news is that overall, U.S. children from all backgrounds are consuming fewer calories then they did a decade ago. Consumption of fast food has declined and children are also more physically active, the researchers said. 
 
Despite the healthy changes, average energy intake has fallen more among children from wealthy, educated homes, Putnam's team found. 
 
Obesity reflects a complex interplay between genetic, metabolic, cultural, environmental and behavioural factors. For example, the researchers said a lack of community recreational centres and sidewalks can stand in the way of children being physically active.  
 
In low-income areas, the only options for groceries could be convenience stores and fast foods chains selling foods high in fat, sugar and salt. Low-income families are less likely to own a car and may reach for foods that are shelf-stable instead of fresh fruits and vegetables, the researchers added.  

British surveys have also pointed to socio-economic disparities in childhood overweight and obesity in England