The use of supermarket till receipts to determine the fat and energy intake in a UK population

OBJECTIVES: To validate the use of supermarket receipts as an index of fat and energy intake in a population that buys most of its food from supermarkets. DESIGN: Cross-sectional, prospective dietary survey - feasibility study. SETTING: Households situated within a 20-mile radius of a large (Tesco) supermarket in Leeds. SUBJECTS: Two hundred and fourteen households who spend >or=60% of their food purse in (Tesco and other) supermarkets. RESULTS: Mean daily household purchase of fat, energy and percentage energy from fat contained in food from supermarkets were 185 g, 19.2 MJ and 35.9%. Mean daily household intakes of fat and energy were 190 g and 20.7 MJ, and 35% of energy was derived from fat. Mean household size was 2.4 persons. The association between the amount of fat and energy purchased from supermarkets and the amount of fat and energy consumed by households was strong. 0.90 MJ (95% confidence interval (CI): 0.8-1.0) of energy were consumed for every 1 MJ purchased from supermarkets and 0.76 g (95% CI: 0.64-0.87) of fat were consumed for every 1 g of fat purchased. CONCLUSIONS: The results show a strong association between estimates of the intakes of fat and energy and percentage energy from fat using 4-day food diaries and 28 days of receipts, in populations who buy most of their food from supermarkets. They also show that the fat content of total food purchases from supermarkets is 35.9% energy from fat compared with 33% energy from fat recommended by the Department of Health. This preliminary research indicates the feasibility of and potential for utilising large quantities of readily available data generated from supermarket checkouts in dietary surveys.