Despite numerous public health initiatives to encourage healthy behaviours and improve living conditions the rates of new cases of obesity in elementary school are higher and are occurring earlier in childhood than they were even a decade earlier, according to a new study.

Obesity in childhood and early adolescence can be linked to poor mental health and are often precursors to chronic diseases in adulthood, including diabetes and cardiovascular disease.

The new study, published in Pediatrics, was led by Solveig A. Cunningham, PhD. The multidisciplinary Emory team includes co-senior authors Michael R. Kramer, PhD, K.M. Venkat Narayan, MD, and postdoctoral fellow Rebecca Jones, PhD.

The researchers analysed at what ages children are most likely to develop obesity and which children are at the highest risk. They compared data on children entering kindergarten in 1998 and in 2010 and followed them through fifth grade. The data are nationally representative, so findings can be generalised to children growing up in the United States.

Major findings from the study include:

Approximately 40 per cent of today's high school students and young adults had experienced obesity or could be categorised as overweight before leaving primary school.

Children born in the 2000s experienced rates of obesity at higher levels and at younger ages than children 12 years earlier, despite public health campaigns and interventions aimed at preventing obesity.

The risk of developing obesity in primary school among the most economically disadvantaged groups increased by 15 per cent.
"These worrying data indicate that the childhood obesity epidemic in the United States continues to grow and get more serious. Our knowledge about effective interventions to fight this also seems limited," says Narayan.

"We urgently need an aggressive national strategy for interdisciplinary research and public health to stem the tide of childhood obesity and its consequences in the US and worldwide."

Cunningham adds, "For decades, we have seen the number of children with obesity increasing, in spite of extensive efforts from many parents and policymakers to improve children's nutrition, physical activity and living environments. Have these efforts worked? Is obesity finally receding? Our findings indicate that no, obesity must continue to be a public health priority."