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 $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. Keywords Till receipts Fat Energy Supermarkets Household dietary assessmentOver the course of the last three decades the proportion of household food purchased from supermarkets has increased. A recent survey showed that 90% of UK households purchase most of their food through this route 1,2 . As supermarkets have come to dominate the supply of food in the UK, developments in information technology and marketing have provided the impetus for competing retailers to develop efficient systems for the electronic generation of itemised receipts at the point of sale. Itemised receipts record a detailed prospective list of household food and drink purchased for home consumption, and as such may provide valuable data on the nutritional composition of the family diet, expenditure on food and food purchasing behaviour. The sales data appearing on the receipt also provide the retailer with information that can be used for marketing purposes 3,4 . Products in a supermarket are allocated a unique bar code that enables related information to be held in a database, for example its weight, price and nutritional content. Access to this information can facilitate coding and nutritional analysis of food items on household supermarket receipts and hence most of a household's domestic food supplies. Nelson and Bingham have reviewed established methods of collecting da...

The aim of this study was to compare the energy and fat content of food purchased for home consumption by households comprising mainly overweight individuals (OH), with those comprising mainly lean individuals (LH). 214 supermarket shoppers and their household were recruited from a Tesco supermarket in Leeds (UK). Households collected supermarket receipts and completed a shopping diary for 28-days, and each member of the household completed a 4-day food record. OH purchased food higher in fat (38% total energy from fat) than LH, (34.9%: p = 0.001) and they purchased more energy and fat per adult equivalent, per day than LH (10.05 MJ compared to 9.15 MJ: p = 0.01 and 103 g compared to 86 g : p = 0.001). Households were 15% more likely to be classified as OH for each additional MJ of energy purchased per person, per day, after adjusting for number of children, household size, age, sex and social class. It was concluded that food purchasing behaviour may be linked to the prevalence of obesity in households who shop at supermarkets.