Billionaires John and Laura Arnold are betting that the country's top nutrition researchers can get to the bottom of the obesity epidemic. Courtesy of the John and Laura Arnold Foundation hide caption

itoggle caption Courtesy of the John and Laura Arnold Foundation

This apple-topped salad is one of several products being recalled for potential contamination with the bacteria Listeria monocytogenes Ready Pac, Inc. hide caption

itoggle caption Ready Pac, Inc.

The new nutrition law gives local providers preference when they bid for school food contracts. Christopher Furlong/Getty Images hide caption

itoggle caption Christopher Furlong/Getty Images