Despite interest in studying food purchasing behaviour of ethnic minorities, there is little research on the purchasing habits of indigenous peoples. The objectives of the present study were to determine differences in food consumption habits in non-Mapuche (Chileans), and people of Mapuche origin (the largest aboriginal group in Chile) who vary in their acculturation orientations, and to evaluate the effect of socio-demographic variables on the acculturation of Mapuche individuals. A personal questionnaire was administered to a sample of 400 people in the Araucanía Region and 400 in the Metropolitan Region of Santiago, Chile, stratified by ethnic group. The frequency of consumption of fish and seafood, fruit, "mate" (a typical herbal infusion), soft drinks, and meals in restaurants differed between non-Mapuche and Mapuche with differing acculturation orientations. Acculturation was significantly associated with the consumption of fish and seafood, mate, and meals in restaurants, and with the consumption of ethnic foods. Using the socio-demographic information, a binomial logit model was proposed for unordered (nominal) data, which proved significant as a whole (P < 0.01). Mapuche people who are under 35 years, belong to a higher socio-economic status and reside in an urban area (large or small cities), are more likely to be assimilated to Chilean culture.