Liu X, et al. – An analysis was performed to assess the associations between relative macronutrient intakes and sleep duration, and the potential modification effect of urban–rural residence among the adult Chinese population. The physicians proposed that among adult Chinese, the relative intakes of protein/carbohydrate were correlated with sleep duration, particularly those in rural areas.

• Data from the China Health and Nutrition Survey 2009 was examined.
• The physicians included 9,239 men and women aged 18 years or older.
• They measured dietary intakes using a combination of a 3-day recall and household-based food weighing approach.
• For this study, sleep duration was self-reported as hours of sleeping every 24 h.

• In this study, the participants had a mean sleep duration of 7.9±1.2 h.
• Higher intake of carbohydrate as percentage of total energy was correlated with longer sleep duration (β ± SE = 0.43 ± 0.12, P < 0.001) after multivariate adjustment; and an inverse association was observed for the relative protein intake (β ± SE = -2.12 ± 0.47, P < 0.001).
• The inverse association for protein was only detected in rural residents (β ± SE = -3.30 ± 0.66, P < 0.001), but not in urban participants (ββ ± SE = -0.44 ± 0.74, P = 0.55) (P for interaction = 0.002) after stratification.
• Likewise, for carbohydrate-sleep association, a marginal interaction with residence was observed.