TUESDAY, March 20 (HealthDay News) -- Small stores in two low-income areas of North Philadelphia began stocking healthier foods after changes to a popular U.S. government food-aid program, a new study finds.

The Special Supplemental Nutrition Program for Women, Infants and Children (WIC program) is tailored to meet the nutritional needs of lower-income pregnant women and new mothers, as well as infants and children up to 5 years old. Under the changes introduced in 2009, the program started giving participants vouchers to pay for fruits and vegetables, whole-grain foods such as brown rice and whole-wheat bread, and tofu. Other changes included a switch from whole-fat to reduced-fat milk.

According to the study, the change prompted the corner and convenience stores in the neighborhoods to carry vegetables, fruits, whole-grain products, reduced-fat milk and other healthy food products.

The researchers also found that the changes to the program increased the availability of nutritious foods without increased cost to families or the government.

The study, funded by the Robert Wood Johnson Foundation, was published in the Journal of Nutrition Education and Behavior.

"Changes in the WIC food package helped increase access to healthy foods in two impoverished neighborhoods," lead author Amy Hillier, of the University of Pennsylvania, said in a foundation news release. "Even small corner stores started stocking fruits and vegetables, lower-fat milk and foods that can help residents stay healthy and reduce their risk of obesity."

The researchers assessed 115 stores in two mostly Hispanic and black North Philadelphia neighborhoods. Full-service chain supermarkets had the highest availability of nutritious foods, but corner and convenience stores enrolled in WIC showed major improvements after the program changes.

Even stores that did not participate in WIC began to stock healthier food items, the study found.

The researchers did not examine whether increased access to nutritious foods actually means people in the neighborhoods have healthier diets.

"We think the people frequenting these stores are eating healthier foods but we would need additional research to confirm that," Hillier said.

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