BACKGROUND: Chrononutrition studies suggest that eating later and extending the eating window are linked to higher energy intake and obesity. However, the relationship between chrononutrition variables and dietary intake, as well as with BMI, is still little explored at a population level. This study explored how chrononutrition variables relate to dietary intake and BMI at a population level.
METHODS: We analyzed data from the NHANES 2017-2018, including 2937 participants aged 18 years or older. Dietary intake was assessed by two 24-h dietary recalls. Caloric midpoint, eating window duration, sleep end-first meal and last meal-sleep onset intervals were determined by mealtime.
RESULTS: The findings indicate a trend of increased total consumption of energy (kcal) (p < 0.001; p < 0.001; p < 0.001; p < 0.001), carbohydrates (g) (p = 0.001; p < 0.001; p < 0.001; p < 0.001); protein (g) (p < 0.001; p = 0.008; p < 0.001; p < 0.001), fat (g) (p < 0.001; p = 0.007; p < 0.001; p < 0.001), and sugar (g) (p < 0.001; p < 0.001; p < 0.001; p < 0.001) as the sleep end-first meal interval decreases and the last meal-sleep onset interval, eating window, and energy intake after 8 pm increases, respectively. In addition, our findings suggest a trend of increased BMI in the group with BMI ≥ 30 kg/m² (p = 0.018) as sleep end-first meal interval increases and in the group with BMI < 25 kg/m² (p = 0.006) as the eating window increases.
CONCLUSION: Our findings suggest that eating later and having longer eating window are associated with higher dietary intake and higher BMI.
