J Phys Act Health. 2019 Mar 1;16(3):214-221. doi: 10.1123/jpah.2017-0389. Epub 2019 Feb 24.
This study tested if the timing of meals, physical activity, light exposure, and sleep cluster within individuals and are associated with body mass index (BMI) in a sample of free-living adults (N = 125).
Data were collected between November 2015 and March 2016 at the University of California, San Diego, Children's Hospital of Philadelphia, and Washington University in St Louis. Height and weight were measured, and BMI (kg/m) was calculated. Sleep timing was estimated using actigraphy, and timing of meals, physical activity, and light exposure were self-reported using a smartphone application. General linear models estimated the mean BMI across time categories of behaviors, adjusting for covariates. A latent class analysis was used to identify patterns of timing variables that clustered within individuals and test for associations between identified patterns and BMI.
Later exposure to outdoor light was associated with a lower BMI (P trend < .01). The timing of other behaviors was not independently associated with BMI. The latent class analysis identified 2 distinct groups related to behavioral timing, reflecting an "early bird" and "night owl" phenotype. These phenotypes were not associated with BMI (P > .05).
Timing of exposures to light, meals, sleep, and physical activity were not strongly associated with BMI in this sample.
本研究旨在测试在自由生活的成年人样本中，饮食、身体活动、光照和睡眠的时间是否在个体内部聚类，并与体重指数（BMI）相关（N=125）。
数据于 2015 年 11 月至 2016 年 3 月在加利福尼亚大学圣地亚哥分校、费城儿童医院和圣路易斯华盛顿大学收集。测量身高和体重，并计算 BMI（kg/m）。使用活动记录仪估计睡眠时间，使用智能手机应用程序自我报告饮食、身体活动和光照时间。使用一般线性模型估计行为时间类别内的平均 BMI，并调整协变量。使用潜在类别分析识别个体内部聚类的时间变量模式，并测试识别模式与 BMI 之间的关联。
晚些时候暴露在户外光线下与较低的 BMI 相关（P 趋势<.01）。其他行为的时间与 BMI 没有独立关联。潜在类别分析确定了与行为时间相关的 2 个不同群体，反映了“早起者”和“夜猫子”表型。这些表型与 BMI 无关（P>.05）。
在本样本中，光照、饮食、睡眠和身体活动的时间与 BMI 没有很强的相关性。
