First Baptist Church of Capitol Heights serves as a produce hub for the Capital Area Food Bank. (Marvin Joseph/The Washington Post)

Lillie Austin sat in her wheelchair in Gwynn Park High School’s cafeteria a few days before Christmas, waiting for her number to be called. Last among nearly 100 people, she was anxious to see what was left at the food bank, hoping that the good stuff hadn’t been entirely scooped up and that she could grab a few more collard greens.

The 72-year-old retiree never imagined needing extra help to fill her cupboard, but she is struggling to feed herself. First, the bills from her hip surgery became too much to handle. Then, the grandson she had raised died, and the funeral costs were left to her. The income Austin does receive, she said, doesn’t go far enough at the grocery store for her to eat healthy.

“You never know how much stuff really costs until . . .” Austin said, her words trailing off as she cocked her head and shrugged. “I’ve always been the giver and volunteered to help people. It’s strange to be the receiver and need the help.”

Hunger remains a persistent problem throughout the Washington region, mostly in places such as Southeast Washington and along the Route 1 corridor in Prince William County. And while the hunger rate has declined in the most affluent corridors of Montgomery and Fairfax counties, in Prince George’s County, the number of people without enough food has increased in each of the past three years.

After analyzing data from its new “Hunger Heat Map” technology, the Capital Area Food Bank saw stark trend lines: More than 15 percent of Prince George’s residents lack sufficient food — the highest rate in the metropolitan region. County residents account for a disproportionate 33 percent of the need in the food bank’s service area, the data shows.

Produce is distributed at First Baptist Church of Capitol Heights in late December. (Marvin Joseph/The Washington Post)

The county’s affordable housing stock and proximity to jobs make it an attractive option for families priced out of more expensive markets in Montgomery County, Northern Virginia and the District.

An estimated 909,000 people lived in the county in 2015 — an increase of more than 10 percent since 2000 — and those newcomers typically are paid lower wages than residents of neighboring jurisdictions, census data shows.

“We were slow to realize the extent to which populations in need had migrated to Prince George’s,” said Nancy Roman, the president and chief executive of the Capital Area Food Bank. The organization has committed to investing more than $3 million annually in Prince George’s — an increase of about $1 million — and expanding its distribution points, its community-resource programs and the amount of food handed out.

That means the food bank will be looking for more partner organizations, schools and volunteers to help distribute hundreds of thousands of pounds of food.

The food bank started increasing output this summer and now regularly serves more than 1,100 students after-school and summer meals and provides groceries to more than 4,500 seniors. It has opened nine school-based food markets, a monthly farmers market and a produce hub at a Capitol Heights church.

Claudia Raskin, who runs the nonprofit Community Support Systems, based in southern Prince George’s, has been working with the food bank for years to distribute the food stored in a massive warehouse in Northeast Washington.

Her organization runs food banks several times a week for residents in the more rural communities of Baden, Brandywine and Accokeek. There is always a gap to be filled, she said.

“They are not starving,” Raskin said. “But these are people living on the edge. They are one unfortunate circumstance away from not being able to fill their fridge or just above income for benefits they can’t get . . . but they don’t have enough.”

Joblessness, low wages and illness are the biggest drivers of food insecurity among the people she serves, Raskin said.

Ericka Key of Upper Marlboro is one. The 50-something-year-old woman left work to care for her ailing mother in 2009. After she died, Key experienced her own health problems. Her income now consists of the rental fees she charges tenants staying at the house her mother left her.

“They are not paying enough to keep up with the cost of living,” said Keys, who was waiting to grab honeydew melons and milk at the high school, at one of the mobile markets run by Raskin’s group. “That’s why people find themselves here.”

Prince George’s also has an increasing number of senior citizens, data shows, who live in isolated communities, pay their bills and taxes but are short at the end of the month. Good nutrition is a challenge in places where access to healthy food is limited.

“Green peppers were $1.59 each last I looked. What happened to two for a dollar?” Austin said. “Lemons used to be a quarter. Now they are a dollar each.”

Roman said the Capital Area Food Bank is trying to educate residents about nutrition and cooking. County residents suffer from some of the highest incidences of diet-related and chronic disease in the state.

At the high school, children and seniors, couples and the disabled were waiting to fill their grocery bags and carts. Culinary students demonstrated how to whip up a meal from the food bank’s daily provisions. They made creamed collard greens, sauteed cabbage and honeydew juice.

One of the cooks, Jaylynn Marable, 15, was surprised by the turnout. “You never expect that many people to come out because they don’t have food,” she said. “It makes me feel good to give back.”