Sleep Restriction and the Adolescent Diet: Impact and Mechanisms

描述（由申请人提供）：预防肥胖已成为国家健康的当务之急，在青春期可能特别重要，但特别困难。青少年在饮食选择和活动水平方面形成持久的生活方式，这可能为终身肥胖奠定基础，因此该领域必须确定影响青少年生活方式的新的可变因素。这项研究测试了一个有希望的预防工作的新目标。我们的研究小组收集了试点数据，这些数据建立在儿童和成人实验结果的基础上，表明睡眠限制（SR）会导致青少年摄入更多的卡路里，而不会增加他们的体力活动。如果这些初步研究结果在更大，更明确的研究中得到证实，肥胖预防工作可以通过减轻SR的策略来加强，这在青少年中非常常见。此外，我们对青少年的初步研究结果扩展了先前的成人研究，表明这种效应的机制是甜/甜点食物的奖励价值的特别增加，导致它们被大量食用，被更积极地感知，并在SR期间引起更多与奖励相关的脑区的激活。当青少年因特殊情况或顽固性睡眠障碍而睡眠不足时，确定次要的干预点。然而，在实现这些好处之前，该领域必须克服我们知识基础中的重大差距。我们的试点研究产生了有趣的发现，但规模太小，方法有限，无法确定。其他儿科研究结果几乎完全来自相关性研究，极大地限制了因果推论。成人SR的研究结果也很难适用于青少年，因为多种方法和发展因素。我们建议克服这些限制，一个强大的机制研究，平衡实验的严谨性与现实世界的相关性，在青春期的高风险时期。健康的、非肥胖的14-17岁的青少年将经历一项实验性睡眠操作的随机交叉试验，该试验跨越5个晚上的时间段（模拟学校周），比较（a）~9小时的夜间睡眠，健康睡眠的建议与（B）~6.3小时，这是许多青少年在上学之夜（SR）经历的。对青少年对特定食物的感知和大脑反应的实验室评估将与现实世界饮食和活动模式的测量相结合，以明确测试（a）SR对健康青少年热量摄入和活动的影响，（B）SR对高热量食物的奖励质量的影响，以及（c）热量摄入变化与食物奖励质量之间的联系。分析将进一步探讨肥胖的危险因素是否确定哪些青少年特别容易受到SR对热量摄入的影响。研究结果将对改善肥胖预防和发现肥胖的复杂生物行为机制产生直接影响。

DESCRIPTION (provided by applicant): Obesity prevention has become a national health imperative, and may be exceptionally important yet particularly difficult during adolescence. Adolescents develop enduring lifestyle patterns in their dietary choices and activity levels that can set the stage for life-long obesity, so it is essential that the field identify novel modifiabl factors that impact the lifestyle patterns of adolescents. This study tests a promising new target for prevention efforts. Our group has collected pilot data that builds upon prior correlational findings in children and experimental findings in adults to suggest that sleep restriction (SR) causes adolescents to eat more calories without increasing their physical activity. If these pilot findings are confirmed in a larger, more definitive study, obesity prevention efforts could be augmented by strategies to alleviate SR, which is known to be extremely common among adolescents. Further, our pilot findings with adolescents extend prior adult research to suggest that the mechanism for this effect is a particular increase in the reward value of sweet/ dessert foods, causing them to be eaten in greater amounts, to be perceived more positively, and to elicit more activation of reward-related brain regions on fMRI during SR. Confirmation of these pilot findings will inform the complex bio-behavioral foundations of obesity, and identify secondary points of intervention for occasions when an adolescent's sleep is inadequate due to unusual circumstances or to an intractable sleep disorder. However, before such benefits can be realized, the field must overcome significant gaps in our knowledge base. Our pilot studies yielded intriguing findings, but were too small and methodologically limited to be definitive. Othe pediatric findings have come almost exclusively from correlational studies, greatly limiting causal inferences. Adult SR findings also are difficult to apply to adolescents because of multiple methodological and developmental factors. We propose to overcome these limitations with a well-powered mechanistic study that balances experimental rigor with real-world relevance during the high-risk period of adolescence. Healthy, non- obese 14-17 year-olds will undergo a randomized cross-over trial of an experimental sleep manipulation across 5-night periods (simulating a school week), comparing nightly sleep of (a) ~9 hr., the recommendation for healthy sleep vs. (b) ~6.3 hr., which many teens experience on school nights (SR). Lab assessments of teens' perception of, and brain responses to, specific foods will be paired with measures of real-world dietary and activity patterns to definitively test (a) the effect of SR on te caloric intake and activity of healthy adolescents, (b) the effect of SR on the rewarding quality o calorie-dense foods, and (c) the link between changes in caloric intake and the rewarding quality of food. Analyses will further explore whether risk factors for obesity identify which adolescents are especially vulnerable to the effect of SR on caloric intake. Findings will have direct implications for improving obesity prevention and for discoveries into obesity's complex bio-behavioral mechanisms.