Diet Composition and Objectively Assessed Sleep Quality: A Narrative Review.
Level 5 - mechanism / opinion, no new human data
Narrative review without systematic search protocol or quantitative pooling
PubMed 35063665 · doi:10.1016/j.jand.2022.01.007
What was done
Authors searched PubMed for studies published between 1975 and March 2021 investigating the relationship between diet composition (macronutrients or specific diets) and objectively assessed sleep quality. The narrative review synthesized 20 human studies, comprising 6 observational and 14 interventional designs.
What was found
The abstract reports no numerical values, effect sizes, or confidence intervals. Total carbohydrate and fat intakes showed mixed associations with sleep quality. Diets higher in complex carbohydrates (such as fiber), unsaturated fats, and protein were associated with better sleep quality. Overall, dietary patterns rich in fiber, fruits, vegetables, and anti-inflammatory nutrients and low in saturated fat (such as the Mediterranean diet) were associated with better objective sleep quality indices.
Why it matters
This review highlights how overall diet quality and macronutrient sources relate to objective sleep parameters, pointing toward diet modification as a potential lifestyle approach to improve sleep.
Limits
The paper is a narrative review rather than a systematic review or meta-analysis, and the abstract omits quantitative results and participant counts. The underlying studies are largely constrained by short durations, testing isolated nutrients rather than whole dietary patterns, and reliance on laboratory settings rather than free-living environments.
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