Food security is especially important for children because their nutrition affects not only their current health, but also their future health and well-being. Previous studies that used various data sources suggest that children in food-insecure households face elevated risks of health and development problems, compared with children in otherwise similar food-secure households. The U.S. Department of Agriculture's (USDA's) domestic food and nutrition assistance programs improve children's food security by providing low-income households with access to healthful food, as well as to nutrition education. Knowledge about the extent of food insecurity in households with children--and the household characteristics associated with food insecurity--contributes to effective operation of these and other programs that support the well-being of children. This report describes the prevalence and severity of food insecurity in households with children as of 2007, the trends since 1999, and characteristics of households affected by food insecurity. [For the associated report, "Food Insecurity in Households with Children: Prevalence, Severity, and Household Characteristics", see ED508211.]