We keep hearing that Philadelphia needs to eliminate its food deserts so everyone has easy access to fresh meat and produce. It's an important step in fighting poverty. But what exactly should a healthy neighborhood look like?

That was the question posed by this year's Better Philadelphia Challenge, the student competition organized by the local chapter of the American Institute of Architects. The winning entry, by a team from the University of New Mexico, showed idyllic scenes of lush community gardens, compact urban greenhouses, and shady pocket parks, all sensitively threaded into a typical rowhouse neighborhood.

OK, maybe the renderings were a bit too idyllic. But the students were drawing on ideas that have become standard in many cities. Neighborhood farmers' markets are already regular events in Philadelphia, thanks to groups like the Food Trust. People are more likely to seek out fresh food if the purveyors are within walking distance of their homes.

Even though that's become the new prescription for creating healthier cities, Philadelphia officials and local development groups remain stubbornly wedded to an old remedy: the auto-centric supermarket.

At a groundbreaking this month, officials cheered the construction of yet another sprawling shopping center, at Second and Allegheny in the Fairhill section. The $16 million Plaza Allegheny development, which will be anchored by a Sav-A-Lot, was touted as an economic engine that will bring jobs to the predominantly Latino neighborhood. But the idea that any supermarket is better than no supermarket is well past its sell-by date.

Officials defend Plaza Allegheny, which has received $6 million in low-interest government loans, by noting that it will occupy a long-vacant, trash-filled lot. But the site is huge, almost nine acres, and the shopping center's immense parking lot will create another kind of wasteland.

The vast asphalt surface will preserve the gap on a largely intact stretch of Allegheny Avenue, a street still lined with houses and small businesses. With so much pavement to pound, walking to the grocery will be that much less pleasant.

Of course, a large supermarket doesn't necessarily have to be surrounded by a field of asphalt. As we've seen with recent developments on South Street in Center City and on Germantown Avenue in Chestnut Hill, food stores can be integrated into real urban buildings by making parking less of a priority.

Plaza Allegheny's developer, David Groverman, insists a more urban form was impossible at Plaza Allegheny because of the parking ratios demanded by Sav-A-Lot, which still bases its numbers on suburban models. Yet Groverman's own market research shows that nearly 40 percent of the shopping center's customers are expected to come by foot. Once they arrive, they'll have to climb a flight of stairs to reach the stores: Because of the site's topography, the shopping center is built on a plateau, 12 feet above the sidewalk.

Years ago, Fairhill was branded the "Badlands," after then-Inquirer columnist Steve Lopez described its lawless despair in his novel Third and Indiana. The North Philadelphia neighborhood still has its rough spots, particularly the squalid tent city and drug bazaar along the Conrail tracks near Second Street, chronicled by my colleague Mike Newall. That encampment is only a block from the new Sav-A-Lot.

For all that, Fairhill is not a hopeless place. The neighborhood bustles with life, especially along Fifth Street, known as Bloco de Oro - the Golden Block. Its dense, rowhouse streets are packed with well-tended homes decorated with cobertizos, the wrought-iron screens used to enclose front porches. Dotted with storefronts selling everything from freshly slaughtered chickens to clothing, Allegheny Avenue is exactly what a vibrant, walkable urban street should be.

Fairhill also is no food desert. Two blocks west of Plaza Allegheny, at Fifth Street, you'll find Fine Fare, a midsize grocery store where crates of plantains, packages of octopus, and other Puerto Rican food staples compete for shelf space.

Felix Morales, the manager, doesn't expect much competition from Sav-A-Lot. "My main focus is Spanish food, which they don't have," he told me. Did we mention that Fine Fare also offers free delivery?

If Fine Fare isn't to your taste, there's a Cousins market a few blocks east. Less than a mile away on Lehigh Avenue, there are more grocery stores, including another Sav-A-Lot at Eighth Street. Two years ago, the city allowed the developer to demolish a century-old Gothic high school listed on the National Register to make room for that supermarket's parking lot.

Fairhill is such a desirable place these days, Groverman says, his Plaza Allegheny shopping center will be able to command rents at least 50 percent higher than those he gets at his suburban shopping centers in Malvern and Ardmore. "The suburbs are overbuilt," he explains. That's why shopping-center developers are now scouring Philadelphia for building sites.

"Food deserts don't really exist here, except in Camden and Chester," Groverman says. A recent study by the Reinvestment Fund bears that out. The number of people without access to healthy food dropped 56 percent between 2005 and 2013.

For years, the city has encouraged developers to air-drop alien, auto-centric supermarkets into its rowhouse neighborhoods. That policy has created large, disconnected voids in places like Parkside and Overbrook, and given us the sprawling parking lot of Progress Plaza on North Broad Street, only steps from Temple University's campus. Nearly all were enabled by government subsidies.

No doubt, these shopping centers have their appeal. They make it easy for city residents to buy groceries and household items in suburban style. But the price to the neighborhoods, and Philadelphia's shopping streets, has been high.

Maybe it's time to stop building asphalt wastelands in the name of eliminating food deserts.