Assessing Individual Food Expenditures for Epidemiologic Studies: Recalls, Records, and Receipts

Abstract

Epidemiologic studies of the relationship between diet composition, cost, and health require assessment of individual food expenditures. While dietary exposure variables are expressed per person per day, food expenditure data are typically collected per household per month. Few studies have reported true individual food costs or the methodology needed to do so. This study used food records and receipts to determine individual food expenditures among 160 adults (106 women, 54 men). Participants attended a 2-hour training, kept food receipts for 4 weeks, completed a 4-day food record, and debriefed with the dietitian afterward. Each food eaten was associated with a receipt-based cost where available. Rules were set to deal with restaurant meals, recipes, missing prices, and “free” foods. Daily dietary intakes were analyzed, then linked to daily food expenses and analyzed for the association between dietary energy density and cost. Preliminary analyses indicate 92% (range 77–100%) of the foods eaten were associated with a receipt-based cost using the 4-week receipt collection method. This study links economic considerations in individual food choice behavior, such as food prices and diet quality, with classic methods of dietary intake assessment. Supported by USDA Cooperative State Research, Education, and Extension Service (CSREES) grant 2004-35215-14441 and NIDCR fellowship T32 DE07132.