Tianna Gaines watches as her year-old twins Marques, left, and Marianna Turner have juice Thursday at their home in Philadelphia. Gaines was a participant of the “Witnesses To Hunger” photo exhibit in Philadelphia. Mariana Chilton, who for years directed statistical studies about hunger and food insecurity — without hearing the stories of the people that bore the statistics_ doled out digital cameras to inner-city mothers and made them the chroniclers of a plight too often ignored.

Philadelphia ? An office party goes on without her, across town in an affluent world vastly different from the one where Mariana Chilton now finds herself. Her husband’s tried calling. Twice.

And still she sits in dress slacks and stocking feet, gray suede shoes tossed aside, on the drab carpet of a row house in the Philadelphia projects, playing with someone else’s children while her own three kids wait for Mom to come home.

A mouse scurries by, but Chilton doesn’t flinch.

She is listening, for the umpteenth time, as another mother speaks about what it means to be poor and hungry in America.

About how this mom scrimps and stretches by adding more than the usual amount of water to powdered milk to make it last. And how, at times, she makes chicken for her children but eats Oodles of Noodles herself. About the $50 bucks left on the food stamp card that must carry this family two more weeks.

Tianna Gaines is her name. She is 29, black, with twin babies and a toddler, facing eviction because she’s $300 behind on rent.

The government calls circumstances like these “food insecurity.” Chilton knows the term well, although she can’t personally relate to its consequences. She is 40, white, Harvard-educated, raised on Martha’s Vineyard. She lives miles from here, in a nice brick house with a nuclear physicist husband and children who eat three square meals a day.

For years, Chilton directed statistical studies about food insecurity without hearing the stories of the people behind the statistics, without really recognizing what hunger means here, in her back yard and yours and mine.

• • •

“Where is one of my favorite photos?” Chilton scans a wall of frames inside an exhibit hall at Drexel University. She stops at one, brushing the glass as if to caress the child herself. “Let me tell you about this kid.”

The little girl, 15-16 months old, wears a striped top that swallows her tiny arms. Her nose is runny, her eyes empty.

Hers is not the picture of hunger that Americans are accustomed to seeing. She isn’t emaciated, like those living in squalid conditions in famine-stricken countries, but she is underweight and malnourished, often fed chips and sugary drinks instead of milk and formula.

The very word, hunger, means something different in 2009 in America. It manifests itself in poor diets lacking in fruits and vegetables, in children who are fed fatty, cheap foods like hot-dogs or ramen noodles and may be overweight but also hungry. It shows in a child’s health, and in the everyday hard choices of mothers and fathers: Buy Pampers or formula? Pay the heating bill or fill the fridge?

Even before the economy tanked, some 36 million adults and children struggled with hunger in 2007, including 12 million the government considers to have “very low food security” — meaning they suffered a substantial disruption to their food supply at some point during the year.

The number of Americans receiving food stamps reached an all-time high last year, topping 30 million in September, October and November, even though the maximum benefit for a family of four — $588 — still falls $78 short of the cheapest possible government-established plan to feed a family that size.

President Barack Obama, whose own mother once received food stamps, has pledged to end childhood hunger; the administration’s stimulus package raises food stamp benefits by 14 percent.

What bothers Chilton is that the numbers, startling as they are in a country as rich as this one remains, seem to do little to effect lasting change. And that’s not an easy thing for a number-cruncher to admit.

An epidemiologist, folklorist and assistant professor of health policy at Drexel, Chilton has spent the last five years conducting research on hunger. Her assistants would park themselves in an emergency room, gathering data from low-income mothers whenever a health crisis brought them and their children to the hospital.

Four years ago, she helped launch a clinic that monitors nutrition in underweight children. And she frequently testifies before Congress about hunger. Still, her work left her with a nagging thought: “There’s something greater that we could do here.”

So when she learned she’d won a $100,000 award in late 2007, she ignored suggestions that she take a vacation and instead started work on “Witnesses to Hunger.” She purchased digital cameras and distributed fliers to some of the mothers who had been interviewed over the years.

“Speak. Teach,” it said. “We want to learn from you.”

• • •

The text message arrives just after 9 in the morning from Barbie Izquierdo, 21 years old, a mother of two.

“Im at salvation army. i would like u 2 c this. i’ve been here since 8.”

Chilton is driving the streets of Philly in a downpour to visit one mother after another. She finds Izquierdo inside a sprawling sanctuary packed with hundreds of people waiting to pick up donations.

Izquierdo, already late for work, holds a slip of paper with her number in line: 633.

“Who are all these people?” Chilton asks her.

“People just like me,” she says.

She works full-time at a rent-a-center store. She takes two buses to bring home $9 an hour, $268 net every week. When she submitted her pay stub to the welfare office, a letter came in the mail saying she was ineligible for food stamp benefits. “PURCHASE OWN FOOD,” it stated.

If only it was that easy. Izquierdo pays $400 in housing every month, $80 for daycare, $54 for the phone, $60 for electricity, $80 on diapers and baby wipes, another $80 or so on transportation, leaving a few hundred dollars for food, health care and anything else she needs for herself, her 3-year-old daughter Leylanie and 1-year-old son Aidan.

“As of yesterday, I had 4 cents on my debit card,” she says.

Izquierdo, a bony 5-foot-8 who dreams of college and a criminal justice career, was Chilton’s inaugural project participant.

Her first photograph showed a neighbor’s kitchen, covered in sewage and streaked with dirt. When Chilton saw this, she understood that hunger goes far beyond what’s in someone’s stomach. It is the life that exists all around them, “a vortex of very negative experiences,” she calls it.

The photographs of the 40 mothers who joined the project depict that vortex, in stark reality.

Blood on the sidewalk in one mother’s neighborhood. Marijuana bags next to a playground slide. Foodstuff hidden behind piles of clothes so it’s not eaten too fast.

• • •

Chilton calls her mothers agents of change. They call her their Dr. Phil.

In truth, she is part therapist, cheerleader, sister, savior and, most of all, their friend.

The photographs have all come down, for now — although Chilton was invited to show the exhibit in Washington, D.C., this spring. She wants to bring some of the mothers, too, and finally have these “real experts” talk to members of Congress.

In the meantime, she still visits them. And they still call. They call when they’re short on rent, not to ask for money but to lean on their new ally. They call with good news, too. When a co-worker offered financial assistance to Smalley, the first person she called was Chilton.

She listens to their stories, offers advice, rubs their backs, wipes their tears, tries to help monetarily when she can — buying them lunch, dipping into another project to purchase a refrigerator for Gaines when hers busted.

“I care so much about the women and I care so much about their children … but I know that helping them with a little money here and there helps them just enough,” she says. “It takes widespread policy change to have a true impact.”