Purpose The social sciences have extensively studied meals; nonetheless, a few have investigated the menu format, with all the data originating from European countries. Within this framework, the novelty of this research is that it analyses the relationship between social class and lunch structure among adults in a Global South city: Santiago, Chile. Design/methodology/approach The study worked with data from the Survey of Commensality in Adults (>18) of the Metropolitan Region, which used a questionnaire and a self-administered eating event diary. The analysis unit was lunches (n = 3,595). The dependent variable was the structure of the lunches (single course, starter with a main course, a main course with dessert or a full-course menu with starter, main course and dessert). The independent variable was the individual's social class (either the working, intermediate or service class). Findings The data showed that lunches are mostly semi- or fully structured (only 44.5% of the lunches reported by the participants contained a single course). The odds of eating a single course were lower in the service class than the working one and the odds of eating a full-course meal were higher in the service class than the working one. Originality/value The results provide new quantitative evidence from a representative sample of a Global South city about the relevance of social class as a differentiating factor in food, specifically regarding the existence of simpler meals among the lower classes.