"Consider this," Ross Fraser of Feeding America wrote in an e-mail. "If you buy a can of tuna fish and donate it to a food bank, it will cost you a dollar and some change." However, a $1 donation to Feeding America provides "about 20 pounds of food and grocery products to someone at risk of hunger."
Other food banks rate their return on your dollar at anywhere from five to 15 pounds of food. They do it by buying in bulk, using volunteer labor and working with food brokers who notify them of deep discounts.
Food bank donations: Top 10 needs - MSN Money