At least, not too many places around this part of North Baltimore.

Johnson had long grown used to leaving the city once or twice a month to get fresh fruits and vegetables, paying high prices and carting them back to her apartment by bus. But that changed five years ago when nearby Loyola University established the FreshCrate program, using its food-service company to sell produce at cost to five small stores on York Road. Now Johnson buys fresh fruit three blocks from home, on the western edge of Govans, a neighborhood where nearly half of the kids live in poverty. FreshCrate, part of Loyola’s neighborhood outreach efforts, is just one of several programs that Baltimore nonprofits, universities and city government have sponsored over the past 15 years to combat a national obesity and diabetes epidemic by bringing bring more healthy foods to low-income neighborhoods where diet-related illness is highest and healthy food choices are most scarce.

Khawar Jamil, the owner of Family Food Market, says 20 to 30 customers a day come in to buy produce, some paying with cash, some with FreshCrate coupons distributed at a nearby free-food pantry. FreshCrate produce fills several wooden produce racks and fridges. Everyday foods are most popular: onions, grapes, strawberries, apples. FreshCrate’s offer to stock the store with fresh food filled a need, says Jamil, who has run the store for 15 years and is known to his customers as Mr. Jimmy. “People were asking me, ‘You have a tomato?’” he recalls. Giant Food, the nearest grocery store, is more than a mile away in suburban Towson. “But if you know it’s only one block, you can come here, you can send your kids to go get it.”

So-called food deserts like Johnson’s neighborhood in north Baltimore have become a buzzy concept in talk about urban inequality in recent years, an easily understood feature of left-behind neighborhoods. The absence of amenities like supermarkets is not just an inconvenience. There is a health consequence, too. In fact, health officials say that a lack of access to healthy food is a factor in obesity, diabetes and high blood pressure. Almost 40 percent of all Americans are obese, including 47 percent of blacks and Hispanics. Obesity is especially prevalent among the poor. So cities like Baltimore—where half of all low-income residents are obese—bear a heavy share of the economic costs of obesity-related illnesses, which account for an estimated 10 percent to 21 percent of all U.S. health-care spending and more than $8 billion a year in workers’ lost productivity. A 2009 Gallup study estimated that obesity-related conditions cost the nation’s 10 most obese cities $50 million a year per 100,000 residents.

But changing health outcomes by changing eating habits has proved to be one of the more vexing challenges facing cities. No one knows this better than Baltimore, which has emerged over the past decade as a national laboratory for urban healthy food experiments. Studies by Johns Hopkins have proven that carefully cultivated partnerships with corner stores, carry-out restaurants and recreation centers can increase sales and consumption of healthy foods and even help kids lose weight. University public-health researchers have mapped Baltimore’s food environment, helping the city designate Healthy Food Priority Areas—a term the city now prefers over food deserts. Baltimore’s city government, one of the few in the nation that has a full-time food policy director and staff, has leaned on Johns Hopkins’ research to figure out what works—and just as important, what doesn’t—to make decisions about what programs to invest in. The first round of city grant funding, coming this year, will include a grant to FreshCrate.