Wal-Mart Corporation announced plans on Wednesday to contribute $2 billion in cash and food to the nation’s food banks, one of the largest corporate gifts on record.

Over the next five years, the giant retail company will distribute some 1.1 billion pounds of food to food banks and provide $250 million to help those organizations buy refrigerated trucks, improve storage and develop better logistics.

“Hunger is just a huge problem, and as the largest grocer in the country, we need to be at the head of the pack in doing something about it,” said Margaret McKenna, president of the Wal-Mart Foundation.

While the economy seems to be turning around, the number of people turning to charities to help put food on their tables continues to grow. A recent survey by Feeding America found that 37 million people a year now use its national network of food banks, a 46 percent increase from 2006. The survey drew on interviews with more than 61,000 people who use food banks, as well as reports from 37,000 food banks across the country.

Put another way, 1 in every 8 Americans uses a food bank to make ends meet, the survey said.

More than one-third of those surveyed said they would not have been able to pay for basics like rent, utilities and medical care without relying on food banks to offset the cost of their meals — and more than a third said at least one person in their household was working.

“It is not just the unemployed that are going hungry,” said Vicki B. Escarra, chief executive of Feeding America.

Wal-Mart began taking on hunger as a cause in 2005, when it distributed 9.9 million pounds of food to food banks; last year, it provided 116.1 million pounds of food. The company also has donated the services of its staff to help food banks improve lighting and refrigeration, and develop ways to increase the amount of fresh food on their shelves.

“We’ve learned a lot about this problem and the kinds of things we can do to help,” Ms. McKenna said. “We’ve learned, for instance, that there is a huge gap in terms of the protein and fresh produce that food banks can deliver, so we’ve learned how to fast-freeze things like meat and dairy. You can’t put 100 pounds of bananas on a truck that isn’t refrigerated and expect them to be edible for long.”

Almost one-third of the food Wal-Mart is donating this year will be fresh, and one of the first cash gifts out of the new grant will go to increasing the number of refrigerated trucks delivering food to food banks. “These are the types of resources we don’t get much from other sources,” Ms. Escarra said.

Wal-Mart and other companies currently are focused on how to get food to children to expose them to fruits, vegetables and meats that traditionally have not been available to poor families because of limited supplies or high cost. For instance, the Target Corporationon Tuesday announced a $2.3 million program to create pantries in schools that can be used to teach children about good nutrition at the same time they are fed.

Target provided an additional $1.2 million to Feeding America to support other school-based feeding programs.

Ms. McKenna said she was concerned about getting food during the summer to children who rely on school breakfast and lunch programs. “We know about sending kids home with backpacks of food for the weekends,” she said, “but what do we do to feed them when they aren’t going to school?”