Doctoral Dissertation Research in DRMS: The effects of weight status and sleep duration on adolescent cognitive functioning and food choice

肥胖是我们国家主要的公共健康问题之一。2017年，超过30%的美国高中生超重（15.6%）或肥胖（14.8%），美国的平均体重指数继续上升。总的来说，这种上升趋势与较早的死亡率和较低的生活质量有关。减肥干预措施通常以食物摄入和运动为目标，但这些干预措施后体重减轻的维持效果很差。因此，确定除食物摄入和运动之外的其他因素可能有助于改善超重和肥胖的预防和治疗，这一点很重要。这项研究的目的是通过调查睡眠和认知功能（如冲动）与体重的关系来做到这一点。过去的研究表明，认知功能差可能会导致不健康的食物选择。睡眠不足可能会加剧这一问题，尤其是超重和肥胖的人，他们在睡眠不足后更容易受到认知功能变化的影响。考虑到这些关系，睡眠可能是防止体重增加和改善肥胖干预措施的一个目标。然而，需要更多的研究来了解体重、睡眠、认知功能和食物摄入量之间的关系。这项研究通过让体重正常的青少年和超重或肥胖的青少年完成两种睡眠条件来调查这些关系，一种是他们连续两晚睡4.5小时，另一种是连续两晚睡9小时。在每一种情况下，都有一份自助早餐和认知功能测试，以评估体重状况和睡眠时间对食物摄入和认知功能的影响。这些发现为当前的肥胖预防计划和减肥干预提供了信息，并加深了对体重增加相关因素的了解。超重和肥胖（OWOB）传统上是通过能量平衡来解释的，减肥干预的重点是减少食物摄入和增加能量消耗。然而，针对这些机制的干预措施往往不能产生肥胖的长期变化。因此，确定其他可修改的机制至关重要。例如，执行功能的各个方面，包括认知灵活性和冲动性，已被证明在OWOB患者中受损，这可能预示着食物消耗的增加。重要的是，睡眠限制在青少年OWOB中很常见，也会损害认知功能。此外，目前的功能磁共振成像证据表明，与体重正常的同龄人相比，患有OWOB的青少年在睡眠限制后更容易受到奖励敏感性变化的影响。然而，这种关系与基于表现的认知功能之间的关系尚未得到很好的评估。因此，本研究旨在通过探索肥胖、睡眠和基于表现的认知功能与观察到的食物选择的关系来扩展现有文献。采用随机交叉设计，NW和OWOB的参与者将按随机顺序完成两种条件：睡眠受限条件下，参与者连续两晚睡4.5小时；睡眠充足条件下，参与者连续两晚睡9小时。条件被两个晚上的冲洗期分开，以防止结转效应。在每个睡眠状态的最后一晚，参与者禁食10个小时，然后参加早上的实验室访问。抵达后，他们会得到一份自助早餐，包括天然和加工过的早餐，并对食物的选择进行衡量。自助早餐后，参与者完成Stroop测试和NIH工具箱认知电池。评估的主要关系是：1)体脂率与食物选择结果和认知功能之间的关系；2)睡眠和体脂率在预测食物选择和认知结果中的独特作用及其相互作用；3)在充分休息和睡眠不足条件下，认知功能在肥胖与食物选择关系中的调节作用。总的来说，这些发现加强了对OWOB和食物选择背后的认知机制的基本理解，为健康行为、生理学和认知神经科学等领域的未来研究提供了框架。该项目为肥胖预防和治疗方案以及有关青少年学习环境和睡眠指南的公共政策提供信息。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Obesity represents one of our nation’s leading public health issues. In 2017, over 30% of U.S. high school students had either overweight (15.6%) or obesity (14.8%), and the average U.S. BMI continues to rise. Overall, this increasing trend is associated with earlier mortality and lower quality of life. Weight loss interventions typically target food intake and exercise, but maintenance of weight loss after these interventions is poor. Therefore, it is important to identify other factors beyond food intake and exercise that may contribute to improved prevention and treatment of overweight and obesity. This study aims to do this by investigating the roles of sleep and cognitive function (e.g. impulsivity) in relation to weight. Past research has demonstrated that poor cognitive function may lead to less healthy food choices. Poor sleep may exacerbate this problem, particularly in individuals with overweight and obesity that may be more vulnerable to changes in cognitive function following short sleep. Given these relationships, sleep may represent a target to prevent weight gain and improve obesity interventions. However, more research is needed to understand the relationships between weight, sleep, cognitive function, and food intake. This research investigates these relationships by having adolescents with normal weight and with overweight or obesity complete two sleep conditions, one in which they sleep for 4.5 hours for two nights and one in which they sleep for 9 hours for two nights. Each condition is followed by a self-serve breakfast and tests of cognitive function to assess the effects of weight status and sleep duration on food intake and cognitive function. The findings inform current obesity prevention programs and weight loss interventions and increase understanding of the factors related to weight gain. Overweight and obesity (OWOB) has traditionally been explained through energy balance, with weight loss interventions focusing on decreased food intake and increased energy expenditure. However, interventions targeting these mechanisms often fail to produce long-term changes in adiposity. Thus, identification of additional modifiable mechanisms is critical. For example, aspects of executive function, including cognitive flexibility and impulsivity, have been shown to be impaired in individuals with OWOB and may predict increased food consumption. Importantly, sleep restriction, which is common in adolescents with OWOB, also impairs cognitive function. Further, current fMRI evidence suggests that adolescents with OWOB are more vulnerable to changes in reward sensitivity following sleep restriction as compared to peers with normal weight (NW). However, this relationship has not been well evaluated in relation to performance-based cognitive function. Thus, this study aims to expand on present literature by exploring the roles of adiposity, sleep, and performance-based cognitive function in relation to observed food choice. Using a randomized crossover design, participants with NW and with OWOB will complete two conditions in a randomized order: a sleep-restricted condition in which participants sleep 4.5 hours for two nights and an adequate sleep condition in which participants sleep 9 hours for two nights. Conditions are separated by a 2-night washout period to prevent carryover effects. On the last night of each sleep condition, participants fast for 10 hours overnight before attending a morning lab visit. Upon arrival, they are given a self-serve breakfast of whole and processed breakfast foods, and food choice is measured. Following the self-serve breakfast, participants complete the Stroop test and NIH Toolbox Cognition Battery. Key relationships assessed are: 1) the relationships between body fat percent and outcomes of food choice and cognitive function; 2) the unique effects of, and interaction between, sleep and body fat percent in predicting food choice and cognitive outcomes; 3) the effects of cognitive function as a moderator in the relationship between adiposity and food choice when adolescents are adequately rested and sleep restricted. Overall, the findings strengthen foundational understanding of the cognitive mechanisms underlying OWOB and food choice, serving as a framework for future research in fields such as health behavior, physiology, and cognitive neuroscience. This project informs obesity prevention and treatment programs as well as public policy regarding adolescent academic environments and sleep guidelines.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.