08/29/2011 01:05 pm ET | Updated Oct 29, 2011

Do You Live in a Food Desert?

To me, better health means eating better and getting more exercise! Grocery shopping is something most of us do at least once a week. I recently heard a travel host talking about how great it is to be close to three local bakeries, several butcher shops and half dozen local grocery stores within an easy 10 min walk -- of course this travel host was talking about a large European city. In the United States, however, most of don't walk to the nearest grocery store, we drive our car.

When we do go to the grocery store, we may not even buy wholesome foods -- let alone fresh fruits and vegetables. If physical proximity to a grocery store (stocked with wholesome foods) is critical to getting and staying healthy, then it is crucial for us to find a way to be assured that grocery stores are located within easy reach -- both physically and financially. Just as we have come to recognize the need to "treat" unacceptable rates of crime, poverty, disease, and the unavailability of parks and safe places to walk, we should be considering access to wholesome, quality food at reasonable prices.

For years, people have been talking about food deserts: "urban neighborhoods and rural towns without ready access to fresh, healthy and affordable food" as defined by the U.S. Department of Agriculture (USDA). These "deserts" are essentially geographical places that lack "reasonable" access to a grocery store.

Defining "reasonable" is a relative term since the 20-something couple living in an upstairs apartment in a large, urban environment may have no problem running through city streets to buy groceries at a store three miles away. However, the woman down the hall in the adjacent apartment who had a hip replacement last year may not have the stamina to walk more than a few blocks with heavy bags.

How many "food deserts" are we talking about?

According to the USDA's Economic Research Service (ERS) report, over 23 million Americans live within a food desert, regardless whether they lived in an urban or rural area. However, physical access to food or groceries can be difficult to measure due to the many factors that create food deserts.

To better understand the problem, an impressive web application launched by U.S. Department of Agriculture (USDA), Food Deserts Locator, and Megacity's Food Desert Finder, were created to display the geographical locations of food deserts, as well as provide estimates of the underserved population by census track. These interactive maps may help increase the public's awareness of the need to improve food access as well as inform real estate developers and grocery store executives of the geographical demands for better access to wholesome foods.

The Johns Hopkins Center for Livable Future recently studied Baltimore's food deserts as part of the Maryland Food System Mapping Project. That study noted that although the generally accepted description of a "food desert" is living more than one mile from a grocery store, supermarket or other food vendor with a variety of fresh fruit, vegetables, dairy and meat, most urban planners claim the acceptable walking distance for public transportation is only ¼ mile. Demonstrating the need for such tools, the Johns Hopkins study used ¼ mile walking distance combined with income data to account for lower income households unlikely to have a car to drive to the nearest available full service grocery store.

We all make food-buying decisions based on personal preference and price, but if you're a working, single parent, are you really going to carve out 45 minutes from your evening to prepare sautéed salmon with vegetables and brown rice? Would you be able to find these foods in a corner convenience store? Throwing a frozen pizza in the oven would be a much faster (and less expensive) dinner solution -- and readily available at most corner stores. One mile for food, but only one quarter of a mile for transportation does not make much sense to me.

As a student of geomedicine, where we live, work and play are intrinsically intertwined with our health and thus with our food choices. The food we choose to eat is all too often a decision influenced largely by what we see and how hungry we actually feel. Making it easier to see, touch and purchase better food seems a worthwhile activity that we all can support.