FRIDAY, March 6 (HealthDay News) -- New research suggests that stores in poor neighborhoods are much less likely to offer healthy foods than those in wealthier parts of town.

"Where you live matters in terms of your diet," said study author Dr. Manuel Franco, an associate professor at Johns Hopkins Bloomberg School of Public Health in Baltimore. "If you live in a neighborhood with no healthy options, it'll be tough for you to change your diet."

Researchers are familiar with the idea that poor people have a harder time getting access to healthy food. But Franco said the two studies his team published are the first to take a look at the issue in a large city; in this case, it was Baltimore. Previous research, he said, only looked at a few neighborhoods or areas.

Researchers visited 226 food stores in the city of Baltimore and Baltimore County -- including supermarkets and convenience stores -- and looked at the availability of healthy food. They then tracked the availability of healthy food in each of 159 neighborhoods.

The findings were published in a recent issue of the American Journal of Preventive Medicine.

The researchers found that 43 percent of predominantly black neighborhoods were in the third of neighborhoods with the least healthy food; 46 percent of the poorest neighborhoods were in that group.

By contrast, just 4 percent of predominantly white neighborhoods were among the third of neighborhoods with the least healthy food. Just 13 percent of the wealthiest neighborhoods were in that group.

A related study by Franco and his colleagues was published in the March issue of The American Journal of Clinical Nutrition. It looked at a survey of 759 Baltimore residents and found that 24 percent of blacks lived in neighborhoods with poor availability of healthy food, compared to 5 percent of whites.

According to Franco, the research suggests that supermarkets, sometimes seen as a panacea for poor neighborhoods, aren't necessarily the answer. "You have to make supermarkets, grocery stores and convenience stores offer a certain amount of healthy food. There are huge variances between the same type of food stores, depending on the neighborhood where they're located."