一项研究报告说，连续5天睡眠不足会增加超出能量需求的食物摄入并且导致体重增加。Kenneth P. Wright, Jr.及其同事就5天睡眠不足对16名成年人的每日能量总开支和总摄入的作用进行了量化。这组作者发现，与受试者被允许睡至多9个小时相比，当受试者被允许睡至多5个小时的时候，平均每日能量开支增加了大约5%。这些受试者的食物摄入也在睡眠不足的时候增加，导致了体重增加。尽管瘦蛋白、胃泌素激素以及发出过量食物摄入信号的YY肽水平发生了变化，受试者还是过度进食。在睡眠不足期间，受试者吃了少量早餐，但是在晚餐后吃了富含碳水化合物、蛋白质和纤维的零食而让热量摄入增加。当受试者从睡眠不足转向睡眠充足的时候，他们减少了热量摄入，特别是减少了从脂肪和碳水化合物中摄入热量，并且减轻了体重。与男性受试者不同，女性受试者在充足睡眠期间维持了她们的体重，但是当她们睡眠不足的时候表现出了饮食限制的减少和体重的增加。这组作者说，该研究证明了睡眠不足可能导致了体重增加的机制。
Impact of insufficient sleep on total daily energy expenditure, food intake, and weight gain
Rachel R. Markwalda,b,1, Edward L. Melansonb,c, Mark R. Smitha, Janine Higginsd, Leigh Perreaultb, Robert H. Eckelb, and Kenneth P. Wright, Jra,b,2
Insufficient sleep is associated with obesity, yet little is known about how repeated nights of insufficient sleep influence energy expenditure and balance. We studied 16 adults in a 14- to 15-d-long inpatient study and quantified effects of 5 d of insufficient sleep, equivalent to a work week, on energy expenditure and energy intake compared with adequate sleep. We found that insufficient sleep increased total daily energy expenditure by ～5%; however, energy intake—especially at night after dinner—was in excess of energy needed to maintain energy balance. Insufficient sleep led to 0.82 ± 0.47 kg (±SD) weight gain despite changes in hunger and satiety hormones ghrelin and leptin, and peptide YY, which signaled excess energy stores. Insufficient sleep delayed circadian melatonin phase and also led to an earlier circadian phase of wake time. Sex differences showed women, not men, maintained weight during adequate sleep, whereas insufficient sleep reduced dietary restraint and led to weight gain in women. Our findings suggest that increased food intake during insufficient sleep is a physiological adaptation to provide energy needed to sustain additional wakefulness; yet when food is easily accessible, intake surpasses that needed. We also found that transitioning from an insufficient to adequate/recovery sleep schedule decreased energy intake, especially of fats and carbohydrates, and led to ?0.03 ± 0.50 kg weight loss. These findings provide evidence that sleep plays a key role in energy metabolism. Importantly, they demonstrate physiological and behavioral mechanisms by which insufficient sleep may contribute to overweight and obesity.
