Use of retailer fidelity card schemes in the assessment of food additive intake: Sunset Yellow a case study.

The feasibility of using a retailer fidelity card scheme to estimate food additive intake was investigated using the Swiss retailer MIGROS's Cumulus Card and the example of the food colour Sunset Yellow (E 110). Information held within the card scheme was used to identify a sample of households purchasing foods containing Sunset Yellow over a 15 day period. A sample of 1204 households was selected for interview, of which 830 households were retained in the study following interview. Interviews were conducted to establish household structure, patterns of consumption by different individuals within the household, and the proportion of foods containing Sunset Yellow habitually purchased at the retailer and/or consumed outside the home. Information provided by the retailer on levels of Sunset Yellow in the foods was combined with the information obtained at interview to calculate the per-capita intake of Sunset Yellow by members of participating households. More than 99% of consumers (n = 1902) of foods containing Sunset Yellow were estimated to consume less than 1 mg Sunset Yellow kg(-1) body weight day(-1). The method proved to be a simple and resource-efficient approach to estimate food additive intake on the basis of actual consumer behaviour and thus reports results more closely related to the actual consumption of foods by individuals.