Dietary supply and reporting reliability during Antarctic overwintering under extreme isolation: a food image-based analysis

Background Objective data on the actual food environment in isolated, confined, and extreme (ICE) settings remain scarce, as planned menus often differ from meals served. This study used image-based documentation to characterize meal composition and sensory properties during Antarctic overwintering and to assess agreement between planned and served meals. Methods More than 2,000 photographs of lunch and dinner plates self-selected by the research physicians at Concordia Station, Antarctica, during three overwintering missions (Mar-Oct) were analyzed. Meals were classified by food group, color, and texture. Planned menus were compared with photographed meals to evaluate agreement. Because documentation varied across missions, analyses were descriptive. Results Meal provision showed limited variation across campaigns and overwintering phases despite differences in personnel and documentation practices. Core food groups consistently dominated meal composition and were photographed on most days, with minor shifts across overwintering phases. Fresh and highly perishable foods declined early and remained minimal during winter, while shelf-stable foods showed broadly similar contributions. Visual appearance and texture profiles showed limited variation on descriptive inspection, indicating a relatively consistent food environment under prolonged isolation. Agreement between planned menus and photographed meals was only moderate (25–47%). Conclusion Antarctic overwintering is characterized by a broadly structured and relatively consistent food environment that persists despite logistical constraints and prolonged isolation. Discrepancies between planned and served meals emphasize the need for objective documentation methods. These insights are relevant for designing and monitoring nutrition systems in other long-duration, confined environments, where image-based approaches may provide a complementary and scalable tool with reduced participant burden and improved ecological validity.