Food Access Impacts Dietary Intervention Effect among Obese African-American Women

Living in a low food access area hinders an individual’s environmental support for a healthy diet. Much research has been conducted to improve food environment or an individual’s diet in low food access areas, but the influence of living in a low food access area on behavioral dietary intervention compliance is still unknown. The purpose of this study was to determine if food access within a residential area influenced a dietary intervention effect.

SISTAS (Sistas Inspiring Sistas Through Activity and Support) is a 12-week dietary and physical activity intervention for obese African-American women living in South Carolina. Participants were randomly assigned to intervention (n=68) or control (n=48) group. Participants in the intervention group received 12 weekly nutrition and physical activity educational sessions. A single 24-hour dietary recall was collected at baseline and post-intervention (12 weeks). Low access areas were defined as census tracts with at least one third of the population or 500 people, living farther than 1 mile (urban) or 20 miles (rural) from the nearest large grocery store, supermarket, or supercenter. Participants’ residential area was categorized two ways: high- and low- food access areas; and low income areas with low food access versus all other areas of income and food access combination. Food and nutrient intake after the intervention was compared between intervention and control group by food access level of their residential area.

After controlling for sociodemographic characteristics and intake at baseline, the intervention group had lower intake of saturated fatty acid and higher vegetable intake (p<0.05) compared to the control group living in high food access areas. In low food access areas, the intervention group had lower intakes of added sugar, sodium, and sweetened beverages (p<0.05) than controls. The intervention effect of improving vegetable intake was significantly greater in high food access areas than in low food access areas (p=0.034). In low income areas with low food access, the intervention group had lower intake of total energy, carbohydrate, added sugar, poly-unsaturated fatty acid, sodium, and sweetened beverages and higher % energy from protein (p<0.05) than the control group. In all other areas of income and food access combination, the intervention group had lower intake of saturated fatty acid (p<0.05) than the control group. Low income areas with low food access showed a significantly greater intervention effect in reducing sweetened beverage intake (p=0.023) and a smaller intervention effect at improving vegetable intake (p=0.072) compared to all other areas of income and food access combination.

The results of this study indicate that the effects of a dietary intervention differ by an individual’s environmental access to food. For more “targeted” interventions, environmental food access is needed to be considered to help individuals successfully overcome environmental barriers to healthy eating.