Division of Epidemiology and Community Health, University of Minnesota School of Public Health, Minneapolis, MN, USA.
Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, University of Minnesota Medical School, Minneapolis, MN, USA.
J Nutr. 2021 Sep 4;151(9):2808-2815. doi: 10.1093/jn/nxab169.
Sleep duration, quality, and timing may influence dietary quality. In adults, poor dietary quality is a risk factor for numerous chronic diseases. It is unclear how these various sleep domains influence adolescents' diets because prior population-based studies have not effectively manipulated sleep, did not include objective sleep measures, and had short follow-up times.
The objectives of this study were to examine 1) how adolescent sleep characteristics relate to dietary quality; and 2) how delay in high school start times (which lengthened sleep duration) affects dietary quality over 2 y.
In the START study, adolescents (grades 9-11, n = 423) attending 5 high schools in the Minneapolis, Minnesota metropolitan area were annually assessed in 3 waves (2016-2018). At Baseline, all schools started "early" (07:30 or 07:45). From Follow-up 1 through Follow-up 2, 2 "policy change schools" shifted to later start times (to 08:20 and 08:50). Three "comparison schools" maintained their early start throughout. Sleep characteristics were measured with actigraphy. Mixed-effect regression models were used to examine cross-sectional and longitudinal associations of sleep characteristics with dietary quality, and school start time policy change with dietary quality change.
Cross-sectionally, later sleep midpoint and onset were associated with dietary quality scores 1.6-1.7 lower (both P < 0.05). However, no prospective associations were observed between sleep characteristics and dietary quality in longitudinal models. Shifting to later school start time tended to be associated with a 2.4-point increase in dietary quality score (P = 0.09) at Follow-up 1, but was not associated with change in dietary quality scores at Follow-up 2 (P = 0.35).
High school students attending delayed-start schools maintained better dietary quality than students in comparison schools; however, differences were not statistically significant. Overall study findings highlight the complexity of the relation between sleep behavior and diet in adolescence.
睡眠时长、质量和时间可能会影响饮食质量。在成年人中，饮食质量差是许多慢性疾病的一个风险因素。目前尚不清楚这些不同的睡眠领域如何影响青少年的饮食，因为之前基于人群的研究并未有效地控制睡眠，也没有包括客观的睡眠测量指标，且随访时间较短。
本研究旨在考察 1）青少年睡眠特征与饮食质量的关系；2）高中推迟上学时间（延长睡眠时间）对 2 年内饮食质量的影响。
在 START 研究中，明尼苏达州明尼阿波利斯都会区 5 所高中的 9-11 年级学生（n=423）每年接受 3 次评估（2016-2018 年）。在基线时，所有学校均“提前”开始上课（7：30 或 7：45）。从随访 1 到随访 2，2 所“政策改变学校”将上学时间推迟到 8：20 和 8：50。3 所“对照学校”在整个研究期间保持早起时间不变。通过活动记录仪测量睡眠特征。使用混合效应回归模型来考察睡眠特征与饮食质量的横断面和纵向关联，以及学校开始时间政策改变与饮食质量变化之间的关系。
横截面上，较晚的睡眠中点和开始时间与饮食质量评分低 1.6-1.7 分（均 P<0.05）相关。然而，在纵向模型中，睡眠特征与饮食质量之间未观察到前瞻性关联。转向较晚的上学时间，在随访 1 时，饮食质量评分平均增加 2.4 分（P=0.09），但在随访 2 时，饮食质量评分无变化（P=0.35）。
上延迟上学时间的高中学生比对照学校的学生保持更好的饮食质量；然而，差异没有统计学意义。总体研究结果突出了青少年睡眠行为和饮食之间关系的复杂性。
