Many of the hungry in this area are fed by elderly women with Jesus in their hearts and comfortable shoes on their feet.

The great surprise of the emergency food network - a system of (depending on the count) 500 to 900 pantries in the city, its suburbs, and South Jersey - is that much of it rests on the able shoulders of a feisty corps of volunteers born before television. They take their marching orders from Christ's teachings to aid the poor.

"They're precious, and if Philadelphia didn't have them, this city would be a disaster," said Steveanna Wynn, executive director of the SHARE Food Program, which supplies city pantries with food.

But lately the landscape of charitable feeding is changing. Depending on the pantry, the clientele has grown between 30 percent and 70 percent in the last economically tough year, antihunger advocates report. And almost half the pantries say they don't get enough food to meet the demand.

What began as a church-based, stopgap effort to help strapped families has morphed into an informal system that many depend on for food.

And now that system - a venerable but rickety patchwork of far-flung pantries run mostly by old people - could itself use some help.

"These pantry people are heroes and saints, but they are being taxed beyond their physical capacity," said Bill Clark, who runs Philabundance, the hunger-relief agency that distributed around 17 million pounds of food to pantries in fiscal 2009, much of it donated by corporations and individuals.

Advocates also worry about a problem that's existed since pantries began opening in the early 1970s: They have sprung up haphazardly, leaving some areas of the city with redundant food distribution and others with none at all.

That's why pantries have to better coordinate and fortify their efforts, advocates say. Both Philabundance and the Greater Philadelphia Coalition Against Hunger are working toward that end.

But change can be slow when food is handed out, bag by bag, by a proud, computer-averse population of micromanagers who aren't grooming successors even as "their bones are cracking," said Derek Felton, a pantry coordinator and staffer of the coalition, an advocacy nonprofit.

"You've got to start thinking differently," Felton told a gathering last week of "hunger fighters," as he calls the sisterhood (mostly) of the pantries. "If something were to happen to you, do you have someone to take your place? How are we going to run programs in the future?"

It's a valid question. In Montgomery County recently, four elderly cupboard managers developed dementia and could no longer stay open, said Patrick Druhan of the county's Community Action Development Commission.

"Hopefully, baby boomers will start volunteering to take the place of those born in the 1920s and '30s," he said.

Until they do, said many of the pantry women at the meeting, they will be willing to undergo training and do what it takes to improve the food-delivery system.

"I will work to open every possible door to get people fed," said the Rev. Gloria Turner, 79, who runs the pantry at Christ Deliverance Center Church in West Philadelphia.

In the complex and kinetic world of charitable feeding, tons of food from the federal government, corporations, and individuals flow into the area, along with streams of money, including $4 million annually from the state for Philadelphia programs.

In Philadelphia, U.S.-supplied food climbed from 170,000 pounds in August 2008 to 425,000 pounds this August, thanks to the federal stimulus, said Wynn, who coordinates federal food and state funding for city pantries. But advocates don't know how long the stimulus help will last.

The food and money are divided among SHARE, Philabundance, and the city's Office of Supportive Housing. Philabundance serves the city and nine nearby counties in Pennsylvania and New Jersey.

Those agencies in turn supply shelters, soup kitchens, and pantries.

At the very end of the pipeline, where food is placed in the hands of people who would go hungry without it, are people like Linese Marvin, 84, who runs the Chapel of Annunciation food pantry in Lawnside, Camden County.