Socioeconomic inequalities in food purchasing: the contribution of respondent-perceived and actual (objectively measured) price and availability of foods.

BACKGROUND: Research has shown that lower socioeconomic groups purchase foods that are less consistent with dietary recommendations. The price and availability of foods are thought to be important mediating factors between socioeconomic position and food purchasing.
OBJECTIVES: We examined the relative contribution of the perceived and objectively measured price and availability of recommended foods to household income differences in food purchasing.
METHODS: Using a face-to-face interview, a random sample of Brisbane residents (n=812) were asked about their food purchasing choices in 2000. They were also asked about their perceptions of the price and availability of 'recommended' foods (i.e. choices lower in fat, saturated fat, sugar, salt or higher in fibre) in the supermarkets where they usually shopped. Audits measuring the actual availability and price of identical foods were conducted in the same supermarkets.
RESULTS: Lower socioeconomic groups were less likely to make food purchasing choices consistent with dietary guideline recommendations. Objective availability and price differences were not associated with purchasing choices, nor did they contribute to socioeconomic inequalities in food purchasing choices. Perceived availability and price differences were associated with the purchase of recommended foods. Perceived availability made a small contribution to inequalities in food purchasing, however perceived price differences did not.
CONCLUSION: Socioeconomic inequalities in food purchasing are not mediated by differential availability of recommended foods and differences in price between recommended and regular foods in supermarkets, or by perceptions of their relative price. However, differential perceptions of the availability of recommended foods may play a small role in food purchasing inequalities.