The association between dietary patterns and quality and duration of sleep in children and adolescents: A systematic review

Background: Dietary pattern has been represented as a contributor to the duration and quality of sleep. This study aimed to review the evidence on this relation among children and adolescents. Study design: This was a systematic review on the association of dietary pattern and sleep. Methods: A literature search was conducted for all articles published between 1980 and August 2020 using the terms "diet" AND "sleep" in PubMed/Medline, Scopus, Web of Science, Cochrane, and Embase databases. Screening and selection of eligible studies were performed by two separate investigators. Studies reporting the impact of different dietary patterns and indices on sleep duration or quality were included. Results: Fourteen publications (12 cross-sectional, 1 cohort, and 1 clinical trial) were identified. Findings from most studies suggested that long sleep duration was consistently associated with healthy dietary patterns, such as "Vegetables & Healthy Proteins", "Traditional", "Fruit & Vegetables", etc. Results were more mixed and inconclusive regarding the quality of sleep, with 2 studies supporting, 2 studies disapproving, and one study neutral about the association between better sleep quality and healthier dietary patterns. The association between diet and sleep seemed to be affected by confounders and covariates, including sex, physical activity, screen time, etc. Conclusions: Longer sleep duration appears to be associated with healthier dietary pattern. However, various results in regard to the relation between dietary patterns and sleep quality preclude definitive conclusions. Further research with standard measures of sleep quality and experimental study designs are needed to better define the causal relationship between sleep and diet. (C) 2021 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.