Via the From Poverty to Opportunity blog:

In 2007, the Greater Chicago Food Depository conducted interviews with 301 working poor residents of Cook County on their level of food security and their usage of food assistance programs . . . .

61% of respondents had experienced food insecurity in the last year. 49% reported three or more conditions of food insecurity.

Of those experiencing some level of food insecurity 30% did not access any kind of food assistance program. Only 22% had used a food pantry. Of the remaining 78% that did not access food pantries, 45% had at least one child in a free or reduced-price school lunch program, 43% had at least one person receiving Food Stamps, 16% had at least one person receiving assistance from Women, Infants and Children.

Follow the link to read the entire post.

Relatedly, Bill Moyers Journal did a powerful show on the growing food crises called "Hunger in America." I highly recommend it. You can watch, listen, or read about the episode here.