Purpose Cross-cultural studies on differences in eating and consumer behavior have several limitations due to differences between countries, for example, in national health policies. Switzerland combines cultural diversity between the language regions, but with a common national health policy. Therefore, Switzerland provides an ideal framework to investigate cross-cultural eating and consumer behavior. The aim of this study was to combine food consumption, purchase data and sales data to obtain a more comprehensive understanding of cultural dietary differences. Design/methodology/approach Six national Swiss studies on food consumption, one study of food sales from the largest supermarket chain in Switzerland and one national study of food purchasing were included. The estimated marginal mean of each food category in each language region was calculated using linear regression and respective linear random effect models. Findings In the French- and Italian-speaking regions more fish was sold, bought and consumed than in the German-speaking region of Switzerland. In contrast, in the German-speaking region, more milk and dairy products were sold, bought and consumed. Language regions explained sales, purchase and consumption of foods, but the findings were only consistent for fish and milk and dairy products. Originality/value If possible limitations of cross-culture studies between countries are eliminated, cultural eating and consumer differences are still visible, even in a small country like Switzerland. For the first time, the complexity of studying food consumption, purchasing and sales is shown in one study. This indicates the importance of further studies which consider these three perspectives to better understand cultural differences in eating and consumption behavior.