Adherence to Lifestyle Medicine and Sleep-Related Problems Among First-Year University Students in Quito, Ecuador, 2024–2025: A Cross-Sectional Study
Background/Objectives: Sleep-related problems are common among university students and are linked to adverse academic and health outcomes. This study evaluated the association between lifestyle medicine adherence and sleep-related problems among first-year Ecuadorian university students. Methods: A cross-sectional study was conducted in Quito, Ecuador, during the 2024–2025 academic year. First-year undergraduate students aged 16–35 years were recruited through a census-based, non-probability strategy (N = 2007). Lifestyle medicine adherence was assessed using the Short Multidimensional Inventory Lifestyle Evaluation for University Students (U-SMILE), and sleep-related problems were defined using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) Level 1 Cross-Cutting Symptom Measure sleep domain (score ≥ 2), a symptom screen that is conceptually related to, but not identical with, the U-SMILE sleep quality domain. Multivariable binary logistic regression models were used and adjusted for sociodemographic and health-related covariates. A post-hoc sensitivity analysis recomputed the global U-SMILE score after excluding the sleep quality domain. Results: The median age was 18.0 years, and 51.0% were female. Among participants with Level 1 sleep data (n = 1906), 47.8% were classified as having sleep-related problems. In the fully adjusted model (n = 1893), higher overall U-SMILE scores were associated with lower odds of sleep-related problems (odds ratio (OR) per 1 point = 0.93, 95% Confidence Interval (CI): 0.91–0.94; OR per 1 SD = 0.56, 95% CI: 0.50–0.62). In a post-hoc sensitivity analysis, this association persisted after excluding the sleep quality domain from the global score (OR per 1 point = 0.94, 95% CI: 0.93–0.95; OR per 1 SD = 0.66, 95% CI: 0.60–0.73). Among non-sleep domains, the strongest associations were avoidance of substance use (OR = 0.87), social relationships (OR = 0.90), and nutrition (OR = 0.90); physical activity, nature engagement, and stress management were also significant. Conclusions: Higher lifestyle medicine adherence was associated with lower odds of sleep-related problems, including in post-hoc analyses when the sleep domain was omitted from the U-SMILE total. These findings support multidimensional lifestyle medicine approaches for sleep health promotion in university settings.