THURSDAY, Nov. 22 (HealthDay News) -- In this land and season of plenty, low-income and rural Americans continue to have difficulty finding healthy foods that are affordable, a new study finds.

One study shows that low-income Americans now would have to spend up to 70 percent of their food budget on fruits and vegetables to meet new national dietary guidelines for healthy eating.

And a second study found that in rural areas, convenience stores far outnumber supermarkets and grocery stores -- even though the latter carry a much wider choice of affordable, healthy foods.

"I think it's a matter of raising awareness among health professionals -- and that could be dieticians or diabetes educators or even doctors -- that when we typically give people a recommendation to eat more fruits and vegetables, that is actually so much more complicated in a rural environment," said Angela Liese, study author of the second report and an associate professor of epidemiology and biostatistics at the Arnold School of Public Health at the University of South Carolina in Columbia.

"There needs to be some thought given to how do you make these recommendations," Liese said.

Both studies appear in the November issue of the Journal of the American Dietetic Association, a themed issue on poverty and human development.

New dietary guidelines recommend that Americans eat nine servings of fruits and vegetables a day, up from five servings in the previous guidelines.

Despite clear evidence that eating your vegetables can ward off heart disease, diabetes and cancer, only 40 percent of Americans meet the old guidelines and less than 10 percent meet the new guidelines, according to one 2006 study.

People with more money eat more fruits and vegetables than those with less money, research shows. In turn, poorer people also assume a greater disease burden relative to their wealthier counterparts.

"Eating more fruits and vegetables would reduce the disease burden. That's why we have new guidelines. The science is very solid on that," said Diana Cassady, lead author of the first study, on food pricing.

"What the profession needs to do is figure out not just the science and appropriate guidelines but how to help people meet those guidelines," said Cassady, an assistant professor of public health sciences at the University of California, Davis.

Cassady's study first calculated the average cost of a "market basket" of fruits and vegetables based on the 1995 Dietary Guidelines' Thrifty Food Plan. They then compared that cost to the cost of a basket based on the 2005 guidelines. The survey was carried out at 25 supermarkets in Sacramento and Los Angeles across three time periods, which allowed for seasonal variations in fresh produce prices.

There was some good news: the 2005 basket actually cost 4 percent less than the 1995 basket, the researchers found. Fruits and vegetables were less expensive in low-income areas and in bulk supermarkets, the researchers noted.

However, a low-income family of four would still have to spend a very large percentage of its food budget on fruits and vegetables in 2005 to meet national healthy-diet guidelines.

"Americans typically spend 15 percent of their food budget on fruits and vegetables but based on our price survey, low-income families would have to spend 40 to 70 percent of their budget on fruits and vegetables," Cassady said. "We really need to rethink what kind of educational campaigns, what kind of advice we need to give low-income families. The food stamp allocation could and probably should be increased and the government can do even better bringing in more farmers' markets and very low-cost sources of fruit and vegetables."

The other study was conducted in Orangeburg County, S.C., a rural county with a population of more than 91,000, 63 percent of whom are minority.

Some 20 percent of Americans live in rural areas but the "nutritional environment" of these areas remains under-explored, Liese's team said.

The researchers identified 77 stores in the county in 2004, of which only 16 percent were supermarkets and 10 percent were grocery stores. The remaining 74 percent were convenience stores.

There were seven stores per 100 square miles and eight stores per 10,000 county residents.

Healthy foods were more available at supermarkets and grocery stores. Low-fat/nonfat milk, apples, high-fiber bread, eggs and smoked turkey were available in 75 percent to 100 percent of supermarkets and grocery stores versus 4 percent to 29 percent of convenience stores. Just 28 percent of all stores sold any of the fruits or vegetables included in the survey -- apples, cucumbers, oranges and tomatoes. Convenience stores tended to charge more for items than did supermarkets.

"The relative availability of healthy versus unhealthy items is way out of whack, so people have much more availability of unhealthy foods," said Tom Farley, co-author of Prescription for a Healthy Nation and a professor of community health sciences at Tulane University School of Public Health and Tropical Medicine in New Orleans. "This suggests that the primary environmental reason why people have unhealthy diets is simple availability."

"There are certain things in public policy that we have the ability to influence and those we don't," Farley continued. "What goes on inside people's heads is tough to influence but we can influence what happens in stores with subsidies, financial incentives, guidelines and public pressure."

More information

Check out the latest federal dietary guidelines at the U.S. Department of Health and Human Services.

SOURCES: Angela Liese, Ph.D., associate professor, epidemiology and biostatistics, Arnold School of Public Health, University of South Carolina, Columbia; Diana Cassady, Dr.P.H., assistant professor, public health sciences, University of California, Davis; Tom Farley, M.D., co-author, Prescription for a Healthy Nation, and professor, community health sciences, Tulane University School of Public Health and Tropical Medicine, New Orleans; November 2007 Journal of the American Dietetic Association