American toddlers – especially Black and Hispanic kids – are too fat, suggesting that parents, and society as a whole, must put greater emphasis targeting obesity in early childhood.

Almost one in five American 4-year-olds are obese, and children of color represent the biggest chunk of that overweight population, according to new research.  In fact, researchers, who calculated the body mass index from a sample of 8,550 Hispanic, Black, White, Asian and Native-American 4-year-olds, found that 18.4 percent of them were obese. But there were wide differences between races.

Significant differences in the prevalence of obesity between racial/ethnic groups were evident at 4 years of age," the researchers wrote in the April issue of the Archives of Pediatrics and Adolescent Medicine.

Using body mass index, they found that 31.2 percent of American Indian/Native Alaskans, 22 percent of Hispanics, 20.8 percent of Blacks, 15.9 percent of Whites and 12.8 percent of Asians were obese.

It's surprising that there are large differences by racial/ethnic group by that age," said Sarah Anderson, an assistant professor of epidemiology at The Ohio State University and lead study author. Anderson and co-author Robert Whitaker's analysis showed that children were becoming obese even before encountering soda and candy vending machines in schools.

These results really do point to the need for us to focus attention on early childhood and the need for research to understand how these differences can emerge so early," Anderson said. "To do that, we may need to understand the different family and cultural factors that are at play in these children's lives.