Screen Time, Sedentary Behavior, Body Mass Index, Sleep Quality, and Psychological Well-Being Among University Students: a Cross-Sectional Study

Abstract

Background: Screen use, sedentary behavior, body mass index (BMI), and sleep are plausible correlates of psychological well-being in university students, but their independent associations and possible gender differences remain inconsistent across studies. Methods: This cross-sectional survey included 49 university students recruited by convenience sampling at a single institution (36 men, 13 women; mean age 20.23 ± 2.06 years). Screen time and daily sitting time were self-reported in ordered categories and coded using category midpoints. BMI was calculated from self-reported height and weight. Psychological well-being was assessed using the WHO-5 Well-Being Index. A study-specific sleep-quality composite was derived from sleep duration, sleep latency, and sleep disturbance items. Associations were examined using Pearson and Spearman correlations, Welch independent-samples t-tests, one-way ANOVA, and multiple linear regression. Results: Screen time (r = −0.092, p = 0.531), sitting time (r = −0.018, p = 0.902), and BMI (r = −0.031, p = 0.836) were not significantly associated with WHO-5 well-being. The study-specific sleep-quality composite showed a positive bivariate association with well-being (r = 0.346, p = 0.015), although its internal consistency was poor (Cronbach’s α = 0.24). No statistically significant gender differences were detected for screen time, sitting time, BMI, sleep quality, or well-being (all p > 0.29). The screen time × gender interaction was not significant (B = −3.58, SE = 6.56, 95% CI [−16.80, 9.64], p = 0.588). The multivariable model was not significant overall (R² = 0.136, p = 0.275); sleep quality was the only individual coefficient reaching p < 0.05 (B = 0.693, p = 0.032). An exploratory uncorrected inverse association between screen time and BMI was observed (r = −0.320, p = 0.027). Conclusion: In this small, gender-imbalanced sample, there was no statistically significant evidence that screen time, sedentary sitting time, or BMI were associated with psychological well-being. Findings concerning sleep quality and the exploratory screen time–BMI association require cautious interpretation because of measurement limitations, multiple testing, and limited statistical power.