How Important Are Dietary Habits Compared to Other Factors for Sleep Quality?—An Analysis Using Data from a Specific Region in Japan

<b>Background/Objectives</b>: The improvement of sleep quality is unquestionably a critical issue in public health. While numerous factors influence sleep quality, the relative importance of dietary habits remains insufficiently understood. The objective of this study is to evaluate the contribution of dietary habits by quantitatively comparing the effects of various determinants of sleep quality. <b>Methods</b>: Using sleep diary data from healthy males and females residing in a specific region of Japan, we estimated a dynamic multivariate panel model (DMPM) to obtain posterior predictive distributions on a scale that allows for comparisons across factor categories. Three outcome variables were adopted to measure sleep quality: presence or absence of daytime drowsiness, ease of falling asleep, and ease of waking up. The determinants of sleep quality examined in the analysis were categorized into six groups: stress factors, bedtime conditions, weather conditions, physical characteristics, exercise habits, and dietary habits. <b>Results</b>: The analysis revealed that although there were some seasonal and gender differences, dietary habits showed effect sizes that were no smaller than those of other determinants across all outcome variables. <b>Conclusions</b>: These results suggest that improving dietary habits, along with enhancing exercise habits and bedtime conditions, is a valid and equally important strategy for promoting better sleep.