Associations of meal timing and dietary macronutrient timing with sleep quality in a diet and physical activity intervention: The Sistas Inspiring Sistas through Activity and Support (SISTAS) study

Background Chrononutrition emphasizes alignment of meal timing with circadian rhythms, as misalignment of eating and sleep behaviors may adversely affect health. Aim We examined the relationship between timing of dietary macronutrients and sleep quality. Methods This post hoc analysis used data from the Sistas Inspiring Sistas through Activity and Support randomized trial. Participants completed the Pittsburgh Sleep Quality Index and a 24-h dietary recall at baseline ( n = 251), 3 months ( n = 159), and 12 months ( n = 127). Meal-timing metrics included clock times for meals and the percentage of daily macronutrient intake consumed after 5 p.m. Linear mixed-effects models adjusted for relevant covariates. Summary Later breakfast timing was associated with poorer sleep quality at 12 months ( β = 0.64, p = 0.02). No significant associations were observed for lunch or dinner timing, or macronutrient intake after 5 p.m. Later breakfast timing may be associated with lower sleep quality. Further studies should explore meal timing and composition in diverse populations.