Examining sleep and social rhythms as mechanisms for weight gain after job loss

描述(由申请者提供)：超重是美国和世界范围内的一大公共健康危机。虽然肥胖的根本原因是能量摄入和消耗的不平衡，但导致这种不平衡的间接原因是复杂的和多方面的。许多研究发现，睡眠不足会增加体重增加的风险和不健康的行为模式(增加卡路里摄入量，减少体力活动)。压力也是肥胖的一个重要间接因素，压力和睡眠不足相互加剧。不幸的是，人们对压力和睡眠是如何在自然环境中相互作用并表现出行为的知之甚少。这项研究的发现将通过提供关于社会节奏、睡眠和非自愿失业后体重增加之间的相互关系的数据，为科学文献基础做出贡献，这是一件经常有压力和 打乱个人的日常生活。研究小组将招募250名参与者，进行为期18个月的前瞻性纵向设计。他们将采用社会节律、睡眠、体重增加、饮食摄入量和能量消耗的黄金标准评估，以进一步明确体重增加的机制。他们还将使用多元增长曲线建模，以获得关于社会节奏、睡眠和体重增加的时间优先顺序的有价值的信息。研究发现：(1)社会节律不太一致且睡眠较差的失业者在18个月内体重增加的轨迹比社会节律稳定且睡眠较好的失业者更陡峭；(2)睡眠紊乱在社会节律紊乱与体重增加的关系中起中介作用；(3)再就业与上述负面轨迹的逆转有关。总体而言，对这些目标的支持将表明，睡眠和社交节奏是在非自愿失业后体重增加的机制。此外，这些发现将通过测试日常行为活动、睡眠和自然环境中的压力之间的相互关系来推动肥胖研究。积极的调查结果将为开展针对易受伤害人群的睡眠和社会节律的预防运动提供坚实的支持。

DESCRIPTION (provided by applicant): Excess body weight is a major public health crisis in the United States and worldwide. Although the essential cause for obesity is an imbalance in energy intake v. expenditure, the indirect causes leading to this imbalance are complex and multifaceted. Numerous studies have found that insufficient sleep increases risk of weight gain and unhealthy behavioral patterns (increased caloric intake, decreased physical activity). Stress is also an important indirect factor for obesity, and stress and sleep deficiency exacerbate one another. Unfortunately, very little is known about how stress and sleep interact and manifest behaviorally for individuals in the natural environment. Findings from this study will contribute t the scientific literature base by providing data about the interrelationships between social rhythms, sleep and weight gain after involuntary job loss, a life event that is often stressful and disrupting to an individual's daily routine. The investigative team will enroll 250 participants ina prospective, longitudinal 18-month design. They will employ gold-standard assessments of social rhythms, sleep, weight gain, and dietary intake and energy expenditure in order to further specify the mechanisms by which weight gain occurs. They will also employ multivariate, growth curve modeling to elicit valuable information about the temporal precedence of changes in social rhythms, sleep, and weight gain. It is proposed that: (1) unemployed individuals with less consistent social rhythms and worse sleep will have steeper weight gain trajectories over 18 months than unemployed individuals with stable social rhythms and better sleep; (2) disrupted sleep mediates the relationship between social rhythm disruption and weight gain; and (3) reemployment is associated with a reversal in the negative trajectories outlined above. Overall support for these aims will indicate that sleep and social rhythms operate as mechanisms of weight gain in the aftermath of involuntary job loss. Moreover, these findings will advance obesity research by testing the interrelationships among daily behavioral activity, sleep, and stress in the natural environment. Positive findings will provide solid support for the development of prevention campaigns targeting sleep and social rhythms in an accessible subgroup of vulnerable individuals.