Influence of Meal Timing and Sleep Variability on Macronutrient Intake and Body Composition in College Undergraduates

 描述（由申请人提供）：在整个发达国家，体重增加和肥胖已经达到了令人震惊的水平。超过30%的美国人肥胖，全球有14亿成年人超重。肥胖是许多代谢疾病的危险因素，在美国每年约占1470亿美元的医疗保健费用。肥胖患病率的最大增长发生在大学年龄段的人群中，这一年龄段是建立长期健康行为的关键发育时期。在夜间进食和可变的睡眠-觉醒时间是体重增加和肥胖的新的潜在风险因素，但对这些风险因素如何影响大学年龄人群的体重和肥胖知之甚少。我们最近发现，大学生在2000小时后消费的膳食数量与相对于体重的较高体脂百分比相关。然而，需要更多关于进餐时间与昼夜生理学和睡眠-觉醒行为之间的关系的细节，因为：（i）与老年人相比，大学生的昼夜节律相延迟，因此2000小时可能不是“昼夜节律”夜晚（即，当褪黑激素升高时）;（ii）在一天中的特定时间的膳食组成可能会不同地影响身体组成;以及（iii）可变的睡眠-清醒时间可能会影响食物摄入的时间。因此，我们提出了一个实验，以确定关联的膳食和睡眠-觉醒时间的变化与体重，身体成分，膳食组成的大学生。这项研究将是对目前资助的NIH R 01项目的补充，该项目是关于社交网络对大学生睡眠的影响。在这项研究中，每个学生在学校参加为期1个月的活动：（i）每天两次完成关于睡眠-觉醒模式的在线日记;（ii）佩戴监测睡眠和觉醒的传感器;（iii）允许他们的移动的手机上的应用程序跟踪电话和互联网的使用情况;以及（iv）在我们的设施过夜以评估褪黑激素的发作（昼夜节律相位的标记和昼夜节律系统开始促进睡眠的时间）。对于这种补充，我们还将使用带有时间戳的移动的电话食物日记跟踪7天内消耗的食物的时间和内容，并记录他们的体重和身体成分（体脂百分比）。将使用每日在线睡眠-觉醒日记和测量每日睡眠时间和持续时间的可穿戴传感器来评估睡眠变异性。这项研究的结果将使我们能够量化在不适当的昼夜节律时间进食，睡眠-觉醒时间变异性，体重，身体成分和膳食成分之间的关系。识别潜在的可修改行为（例如，饮食和睡眠的时间）来降低这一人群的体重水平，对于制定基于研究的战略以减少成年期疾病的负担和高昂费用至关重要。研究结果将提供更多关于昼夜节律、睡眠-觉醒行为和新陈代谢之间关系的信息。这些知识可以用于公共卫生论坛，包括关于食物时间及其对身体成分影响的教育活动。

 DESCRIPTION (provided by applicant): Weight gain and obesity have reached alarming levels throughout the developed world. Over 30% of Americans are obese and 1.4 billion adults worldwide are overweight. Obesity is a risk factor for numerous metabolic diseases and accounts for ~$147 billion in health care costs each year in the United States. The greatest increase in prevalence of obesity rates occurs in the college-aged population, an age that is a critical developmental time period for establishing long-term health behaviors. Eating during the night and variable sleep-wake timing are novel potential risk factors for weight gain and obesity, yet little is known about how these risk factors influence weight and obesity in the college-aged population. We have recently found that the number of meals college students consume after 2000h is associated with a higher percentage of body fat relative to weight. However, more detail is needed on the relationship between the timing of meals with circadian physiology and sleep-wake behaviors as: (i) the circadian phase in college students is delayed as compared to older populations and thus 2000h may not be the "circadian" night (i.e., when melatonin is elevated); (ii) composition of meals at specific times of the day could differently affect body composition; and (iii) variable sleep-wake timing may influence the timing of food intake. We therefore propose an experiment to identify the association of both meal and sleep-wake timing variability with weight, body composition, and meal composition in college undergraduates. This study will be a supplement to a currently funded NIH R01 project on the effects of social networks on sleep in college students. For that study, each student participates for 1-month while at school by: (i) completing online diaries twice daily about sleep-wake patterns; (ii) wearing sensors that monitor sleep and wakefulness; (iii) allowing an application on their mobile phone to track phone and internet usage; and (iv) staying overnight at our facility to assess melatonin onset (a marker of circadian phase and the time at which the circadian system begins to promote sleep). For this supplement, we will also track the timing and content of food consumed using a time-stamped mobile phone food diary for a 7-day period and record their weight and body composition (percent body fat). Sleep variability will be assessed using the daily online sleep-wake diaries and wearable sensors that measure daily sleep timing and duration. The results from the proposed work will allow us to quantify relationships among eating at inappropriate circadian times, sleep-wake timing variability, weight, body composition, and meal composition. Identifying potential modifiable behaviors (e.g., timing of meals and sleep) to reduce weight levels in this population is crucial for developing research based strategies for decreasing the burdens and high cost of disease during adulthood. The results will provide additional information about the relationships between circadian rhythms, sleep-wake behavior, and metabolism. The knowledge can be utilized in public health forums, including educational campaigns about food timing and its effects on body composition.