(Bloomberg News) After losing her job as a consultant for nonprofits, Martha Heassler and her husband, a graphic artist, no longer had money for their daughter's college education, new clothing or groceries.

"We're waiting for my husband's paycheck, and we probably have less than $200 to our name," Heassler, 55, said by phone.

She now makes weekly trips to the Open Door Food Pantry in Gloucester, Massachusetts, to pick up bags of food that include meat, eggs, yogurt and vegetables.

"Without the network of food pantries around us, I don't know how we would have eaten," said Heassler, who holds a bachelor's degree in English literature from Gordon College, in Wenham, Massachusetts.

As the sluggish economy idles more middle-class individuals and families, their donations to food banks and soup kitchens have evaporated, hitting the nonprofits from both ends.

"We're seeing many faces from the middle class who had been donors who now need support from our food bank," Terry Shannon, president and chief executive officer of the Phoenix, Arizona-based St. Mary's Food Bank Alliance, said by phone. "Right now, our donations are softer than we would like them to be."

The Greater Boston Food Bank, which supplies food to Open Door, has had a 23 percent increase in need since 2008 when the U.S. economy entered a recession. Last year, it distributed about 37 million pounds of food, or about 28.2 million meals.

"We're acquiring more food and distributing more food, and the demand always outpaces the source," Catherine D'Amato, president and chief executive officer of the food bank, said by phone.

In the past year, corporate dismissals have left middle-class and white-collar workers stranded from the job market, causing many to seek public assistance and help from food charities.

Only about 7 percent of those who lost jobs after the 2008 financial crisis have found work that matched or exceeded their previous job, according to a study released last month by the John J. Heldrich Center for Workforce Development at Rutgers University. The survey of 1,200 unemployed U.S. workers selected at random was conducted between August 2009 and August 2011.

"The group surveyed was better educated and more affluent, relative to the people who are usually unemployed in this country," Cliff Zukin, a Rutgers professor of public policy and co-author of the study, said by phone.

The percentage of households in the U.S. using food stamps has more than doubled in 6 of the nation's 10 wealthiest counties, according to data compiled by Bloomberg.

"I see people who look like they would be on a lunch break from work," said Violet DeSantis, 46, an unemployed worker in San Francisco who became a volunteer at the St. Anthony Foundation's dining room, which she also turned to for food. "I wouldn't have ever imagined that they would look like that."

The Atlas of Giving LLC forecasts that donations will rise 4.9 percent in 2012, said Rob Mitchell, chief executive of the Dallas-based company. Still, high unemployment "will have a lingering impact" on giving for at least two years, he said.

At Fisherman's Mark, a social-services center in Lambertville, New Jersey, some of the out-of-work regulars have doctoral degrees and "drive up in luxury cars such as Mercedes- Benz," says Gina Davio, Fisherman Mark's program director of social services, by phone. The nonprofit's Hunterdon County had a median household income of $97,874, the highest in the state and the fourth-highest in the U.S. Hunterdon's food-stamp usage rose 513 percent between 2007 and 2010.

"One guy who came in worked at a plant where he made hundreds of thousands of dollars, and he got cut, and I see a lot of people who have a great amount of job experience and big salaries," Davio said. "I see women coming in designer clothes such as Ralph Lauren and who are physically fit."

The rising cost of food-pantry staples such as peanut butter, one of the most requested items by families with children, has "put more strain" on St. Mary's Food Bank's financial resources, Shannon said. The cost of peanut butter distributed in about 40,000 food boxes monthly has increased 15 percent to 20 percent during the past three years.

Although Citymeals-on-Wheels has boosted its fundraiser efforts, direct-mail donations are down about 2.4 percent from a year ago, executive director Beth Shapiro said by phone.

"December is a nail-biting month for us," said Jilly Stephens, executive director of City Harvest, about her hunger charity, which raises 42 percent of its budget between November and January. "It feels like we're always pushing hard, and we continue to see more New Yorkers turning to emergency food."