Statistical analysis:
Distributions of demographic, lifestyle behaviors, and dietary characteristics were compared across sleep quality score and time in bed (hr/d). Hence, we used chi-square test for categorical variables and one-way ANOVA test for continues variables.
The Generalized Additive Models (GAM) procedure was applied to the dataset of 211 without any missing data by smoothening the effect of covariates into crud and adjusted models. Moreover, the adjusted Model include age, sex and total daily energy intake.
GAM uses a link function to establish a relationship between the mean of the response variable and a smoothed function of the explanatory variable(s).
We used SPSS version16 and R version 3.6.2 to perform the analyses. P values <0.05 were considered significant. The FFQ analysis and nutrients were estimated using NUT IV software (Nutritionist IV).