From the Meals on Wheels Research Foundation report:

14.85% of seniors, or more than 1 in 7, face the threat of hunger. This translates into 8.3 million seniors. In contrast, in Ziliak, et al. (2008) we reported that as of 2005 1 in 9 seniors faced the threat of hunger.
Those living in states in the South and Southwest, those who are racial or ethnic minorities, those with lower incomes, and those who are younger (ages 60-69) are most likely to be threatened by hunger.
Out of those seniors who face the threat of hunger, the majority have incomes above the poverty line and are white.
From 2001 to 2010, the number of seniors experiencing the threat of hunger has increased by 78%. Since the onset of the recession in 2007 to 2010, the number of seniors experiencing the threat of hunger has increased by 34%.

http://www.mowrf.org/The2010AnnualReport.pdf

Senior Hunger in America 2010: An Annual Report
Prepared for the Meals On Wheels Research Foundation, Inc.
May 3, 2012
Professor James P. Ziliak Professor Craig Gundersen University of Kentucky University of Illinois