When the U.S. Department of Agriculture (USDA) launched its online Food Desert Locator last summer, Seattle’s gourmets and locavores were horrified to see nutritional wastelands encroaching upon the city.

In all, more than 125,000 people, in neighborhoods everywhere from West Seattle to Renton, live in places where fresh, healthy food is difficult to find—so-called “food deserts.”

First identified in Scotland in the 1990s, food deserts have come to epitomize urban decay. They summon up visions of endless fast-food restaurants and convenience stores serving fatty, sugary junk food to overweight customers who shun fresh vegetables and rarely prepare meals from scratch.

Food deserts do not fit in with Seattle’s self-image as a city that celebrates local chefs, supports a slew of farmers markets and watches what it eats. And yet a glance at the data shows that we do have a serious eating disorder.

According to King County Public Health, in 1990, just 6.2 percent of adults in King County were obese. Today, more than half are overweight and one in five are obese. The obesity rate is even higher (22 percent) among middle and high school students, who are getting up to one-sixth of their daily calories from high-fructose-laden sodas.

King County is not alone; addressing the national obesity epidemic has become a priority for federal health officials, who believe that targeting food deserts can stem the rising tide of obesity and other diet-related diseases, such as diabetes, heart disease and cancer.

Last year, Michelle Obama announced a $400 million Healthy Food Financing Initiative, which aims to eliminate food deserts within six years by expanding access to healthy food.

The problem is that few local experts consider food deserts a useful tool in the war against obesity.

“I don’t like the term ‘food desert,’” says Richard Gelb, a project manager at King County’s Department of Natural Resources and Parks who is working on a food-mapping project using health department data. “I find it way too rudimentary to tell the full story about healthy-food access.”

Adam Drewnowski, director of the Nutritional Sciences Program at the University of Washington, agrees. “There are clearly areas in North America where there are no grocery stores, no supermarkets, and all you see is pizza. Those places do exist, but not in Seattle.” What does exist in the Seattle area, experts say, are dietary problems that span all incomes, education levels and cultures, and are too complex to summarize with lines on a map.

So what exactly is a food desert?

The USDA defines it as any census tract where at least 20 percent of people earn below the poverty line and 33 percent live more than a mile from a supermarket (10 miles in rural areas). There are 17 such tracts in King County, mostly in South Seattle, but extending down through Tukwila to Auburn and Federal Way. You can determine if you live in a food desert by entering your ZIP code into the Food Desert Locator (if link does not work, go to ers.usda.gov and search “food desert”), but Drewnowski and others say that won’t tell you much.

For one thing, the food-desert concept assumes that people shop in their own neighborhoods. In fact, says Drewnowski, lower- and middle-class shoppers drive to other neighborhoods looking for bargains. “Based on our research, there is a supermarket within a 10-minute drive of virtually all homes in Seattle,” he says.

Moreover, simply having a supermarket nearby does not improve dietary health. All supermarkets stock aisles of fresh food, but people all too often roll their carts right past them. Most experts agree that building a brand-new supermarket in a neighborhood will not necessarily change people’s behavior. And Drewnowski says that focusing on food deserts is actually taking the easy way out. “The idea that if a supermarket was half a mile closer, people would be eating fresh raspberries, is ridiculous. [Blaming it on food deserts is] an easier solution than tackling poverty, obesity, unemployment and deprivation.”

And some argue that supermarkets are actually part of the problem, promoting cheap, processed junk food. Safeway may have cheaper vegetables than Whole Foods, but shoppers still shun them; obesity rates among local Safeway shoppers run around five times higher than those of shoppers at Whole Foods, according to a 2010 University of Washington study. And don’t think that building more Whole Foods Markets will help, says Drewnowski. “Living near a Whole Foods can’t help low-income families, because they can’t afford anything once they walk in the store.”

Yet another problem with the food-desert approach is that it ignores sources of healthy food other than supermarkets, such as produce stands, hypermarkets (combined grocery and department stores), specialty grocery stores and farmers markets. By focusing on supermarkets as the solution to America’s unhealthy diet, the government risks wasting funds to subsidize large stores at the expense of smaller, more effective suppliers.

Improving access to those smaller suppliers is the goal of a new initiative by King County. Richard Gelb is now working to create a more accurate food map that features all of the region’s retail food establishments, including street food vendors and restaurants.

“We’re trying to provide a richer, more nuanced portrayal of food access, instead of something as blunt as the USDA food deserts,” he says. Gelb’s plan is to use data from King County’s nearly 10,000 retail food establishments to build a website called FoodScore. “If you go to the site and key in an address, it will identify the nearest farmers market, food bank or full-service grocery store,” says Gelb, who hopes to have the site live by next summer.

There is one upside to the fed’s fixation on food deserts: Even though many of Seattle’s public nutrition experts reject the concept, they welcome the federal money that deserts bring to the table. Seattle/King County has received one of largest awards nationwide for healthy eating: $25.6 million from the Centers for Disease Control and Prevention. This money is funding Richard Gelb’s FoodScore website as well as Healthy Foods Here, a food-access program managed by Seattle’s Office of Economic Development. So far, the federal government is staying relatively hands-off regarding how the money is used, and not insisting on working the supermarket agenda. That’s good news for small, innovative local programs like Healthy Foods Here, which focuses on increasing low-income families’ access to healthy food.

“In south King County, we have obesity and diabetes disparities that we’re trying to address by working with smaller stores,” says Tammy Morales, principal of Urban Food Link, a community development and planning firm that’s part of the Healthy Foods Here program.

“In these areas, there might be a large grocery store, but it isn’t necessarily affordable or selling food that’s culturally appropriate for the community,” she says. “One store had been ordering $50 of produce a week and throwing out half, because the owner didn’t have the right refrigeration and didn’t really know how to stock it. We gave him produce-handling training and helped him purchase a cooler. Now he’s ordering $200 [worth of produce] every week, and his waste has pretty much dropped to zero.”

Another innovative solution, Seattle-based Stockbox, uses reclaimed shipping containers as temporary “pop up” stores full of fresh produce and affordable staples. Started last year as a project by Bainbridge Island MBA student Carrie Ferrence, Stockbox is funded by grant money from Healthy Foods Here and about $20,000 raised via the website Kickstarter. The first Stockbox is now open in an apartment parking lot on the edge of a USDA food desert in Delridge; two more locations are planned for South Seattle in 2012.

These projects are just a drop of fresh juice in an ocean of sticky soda, but Morales remains upbeat: “The current situation in our food system is the result of 50 years of industrialization, and change is not going to happen overnight. But adjust people’s expectations, give them the opportunity to make healthy choices, and eventually people will change their behavior.

“The real benefit of a tool like the Food Desert Locator is that it starts a conversation about what’s happening in our communities.”