Below is a link to the new Economic Research Service study Household Food Security in the United States, 2007. Eighty-nine percent of U.S. households were food secure throughout the entire year in 2007 (access at all times to enough food). Rates of food insecurity were essentially unchanged from 2005 and 2006.
http://www.ers.usda.gov/Publications/ERR66/
This and other reports from the Economic Research Service can provide background and ideas for your stories on food, farming, conservation, and rural development.