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.
睡眠不足与肥胖有关，但鲜为人知的是夜夜难眠如何影响能量消耗和平衡。我们研究了16名住院14到15天的成人病患，量化了5天即相当于一个工作周的睡眠不足，相较于充足睡眠来说，对能量消耗和能量摄入所造成的影响。我们发现，睡眠不足使每日总能量消耗约增加5％; 然而能量摄入尤其是晚上晚饭后额外的能量摄入超过了人体用来维持能量平衡所需的热量。尽管标志着过量能量储存信号的饥饿和饱和激素胃饥饿素与瘦素还有肽YY等发生一系列变化，睡眠不足仍会导致0.82±0.47千克（±SD）体重的增加。 睡眠不足延迟了褪黑激素昼夜阶段并且也导致了较早的清醒昼夜阶段。 性别差异表明女性，而非男人，在睡眠充足下能维持体重，而睡眠不足时则更难维持节制饮食从而导致体重增加。我们的研究结果表明，睡眠不足时的食量增加是为维持额外觉醒时间所需能量所做的生理适应；然而当食物易于获取时，摄入量往往会超过人体所需。我们还发现从睡眠不足过渡到足够/恢复性睡眠阶段减少了能量摄入，特别是脂肪和碳水化合物摄入并导致了-0.03±0.50公斤的重量损失。这些发现提供的证据表明睡眠在能量代谢中发挥着关键作用。重要的是这些发现证实了睡眠不足可导致超重和肥胖的生理和行为机制。