Where you live may determine how healthy you are or can hope to be, according to a new study published in the American Journal of Preventive Medicine. Researchers using a geographic information system (GIS) found that access to quality food outlets and opportunities to be physically active can make communities not only more attractive but also more healthy.

Both children and adults who live in areas that provide supermarkets within reasonable distance, recreational parks and safe sidewalks and bike paths have on average lower rates of obesity, diabetes and heart disease than those living in underserved neighborhoods, including so-called food deserts.

“The biggest difference we found in rates of obesity were in places where the environment was good for both nutrition and physical activity,” said Dr. Brian Saelens, professor of pediatrics at Seattle Children’s Research Institute and co-author of the study report. “The rates [in the best places] were less than 8 percent. But if the nutrition and physical activity were not good, the rates went up to 16 percent.”

Although these findings should not come as a surprise, it is the first time that scientists have used geographic data to specifically investigate the causes of lifestyle-related health problems.

Up to now, most studies on the ever-rising obesity epidemic have been focusing on factors such as lifestyle, income, education and genetic preconditions. Geographic differences should be used more often in the future to assess the connections between nutrition, physical activity and obesity. For instance, if we can count the numbers of grocery stores, convenient stores, fast food restaurants and recreational facilities in a particular area, we may be able to predict better what chances the local population has to live more healthily, the researchers said.

“To address this health crisis, attention must be focused on a key issue that lies at the core of the epidemic: The social inequities of obesity,” said Rear Admiral Susan Blumenthal, MD, MPA, a former U.S. Assistant Surgeon General.

“A significant body of scientific evidence links poverty with higher rates of obesity. Families with limited economic resources turn to food with poor nutritional quality because it is cheaper and more accessible. Low-income families live in neighborhoods where it is dangerous to play outside, reducing opportunities for both children and adults to exercise. Instead of supermarkets, [low-income] neighborhoods may have an abundance of fast-food retailers and corner stores that are stocked with products high in fat and low in nutrients. Families are often targeted by food marketers with advertisements encouraging the consumption of nutrient-poor foods, increasing the likelihood of adopting unhealthy dietary practices.”

Despite of their best efforts to lure more supermarkets to underserved neighborhoods through tax breaks and other incentives, local governments find it hard to overcome the many obstacles they’re facing. The so-called food deserts in many poor urban and rural areas persist because of lack of consumer demand (people don’t have the money to buy nutritious but pricey foods), high crime rates (and insurance costs) and transportation expenses (to remote areas).

An area is officially considered a food desert when it has no supermarkets within 1 mile in an urban setting and within 10 miles in a rural environment. The U.S. Department of Agriculture (USDA) estimates that nearly 25 million Americans live in food deserts.

Social welfare programs such as food stamps bring only limited relief because of geographic hindrances. According to data collected by the Centers for Disease Control and Prevention (CDC) and the U.S. Department of Health and Human Services (HHS), a quarter of all food stamps recipients do not have easy access to supermarkets. High gas prices and lack of private or public transportation only worsen the situation.

Obviously, not all or even many of these conditions can be changed overnight. However, a few small steps in the right direction can go a long way. Communities have taken initiatives all over the country to facilitate more local farmers markets and sales outlets for urban farms where fresh foods are available at affordable prices. Achieving better “walkability” has become a goal in cities and towns of all sizes. With greater awareness, good will and some imagination, we all can make a difference for ourselves and our neighborhood.

Timi Gustafson R.D. is a clinical dietitian and author of the book “The Healthy Diner – How to Eat Right and Still Have Fun”, which is available on her blog, “Food and Health with Timi Gustafson R.D.” (http://www.timigustafson.com), and at amazon.com. You can follow Timi on Twitter (http://twitter.com/TimiGustafsonRD) and on Facebook http://www.facebook.com/TimiGustafsonRD.