Dietary fat and sleep duration in Chinese men and women

Background: Many recent studies have highlighted the complex interaction between sleep duration, food intake and metabolic balance. Although a causal link is yet to be established, emerging evidence suggests that short sleep duration may alter the balance between energy intake and energy expenditure. Thus far, most research has focussed on the link between sleep duration and carbohydrate metabolism. The role of sleep duration in fat intake and vice versa remains relatively unknown. Objective: The aim of this analysis was to determine whether there exists a significant association between sleep duration and fat intake. Design: Data from 2828 adults living in Jiangsu province, China, collected during a national survey of nutrition and health conducted in 2002. Results: The analysis showed a statistically significant association between sleep duration and fat and carbohydrate intake but not protein or fasting blood glucose. Those who slept for less than 7 h a day had significantly higher (P = 0.005) percentage of energy from fat intake than those who slept for 7-9 h per day. Analysis of the influence of high fat intake upon sleep demonstrated a trend to reduced sleep duration between the highest and lowest quartiles of fat intake (P = 0.056). Conclusions: To our knowledge, this is the first data from a large cross-sectional study to show an association between decreased sleep duration and increased fat intake in humans. Given the trend towards decreased sleep duration in modern societies and the parallel obesity epidemic, the significance of this association warrants more research.