Weekday-Weekend Differences in Chrononutritional Variables Depend on Urban or Rural Living.

Background/objectives: Studies have highlighted the impact of work and school schedules on food preferences, suggesting that individuals' dietary choices may change during the week to align with their daily routines. Despite the variation in food composition in the population, there is no evidence identifying differences in food intake times and composition across the days of the week in urban/rural locations. Thus, the study's aim was to identify weekday vs. weekend differences in food intake times and composition (calories) between urban and rural areas.

Methods: Data from 5770 participants (aged 18-59 years) were analyzed from the National Household Budget Survey (POF-IBGE) consisting of two distinct food diary records (weekday + weekend) per individual, including area (urban or rural) information in Brazil.

Results: During weekdays, the time of the first food intake was significantly earlier, and the last food intake time was significantly later compared to weekends, resulting in a longer eating window on weekdays in both urban and rural areas. People living in urban areas exhibited delayed first and last food intake times, resulting in later caloric and eating midpoints compared to people living in rural areas. Periodogram analysis detected weekly rhythmicity (7 days) at the time of the first food intake and the length of the eating window in urban residents.

Conclusions: The observed 7-day rhythmic pattern of food intake in urban areas, driven by work and school schedules, underscores the influence of urbanization on dietary timing and composition. In contrast, rural areas exhibited more stable and earlier eating patterns. These results emphasize the need for public health interventions to address meal timing and circadian alignment, particularly in urban settings, to mitigate the risk of metabolic disorders and improve overall health outcomes.