Predictors of Physical and Mental Health in Sports Science Students: a Focus on Physical Activity, Sleep, and Diet

University students face several lifestyle-related health risk factors, including low physical activity levels, inadequate sleep quality and duration, and poor diet quality, which can contribute to compromised health. This study explores (i) the effect of physical activity levels and being bachelor’s or master’s students on sleep quality, adherence to the Mediterranean diet and health and (ii) how these factors may influence health outcomes in a sample of Italian university students. 436 sports science students answered an online survey assessing physical activity (GSL-TPAQ), sleep quality (PSQI), daytime sleepiness (ESS), Mediterranean diet adherence (KIDMED), and health status (SF-12). Master’s students reported better sleep quality (p = 0.046) and less daytime sleepiness (p = 0.025) than bachelor’s. Independently of graduation state, students in the highest activity tertile reported better mental health than those in the lowest (p = 0.003) and medium tertiles (p = 0.013). Regression analyses identified poor sleep quality as a significant predictor of worse physical (β = − 0.2, p = 0.001) and mental health (β = − 0.35, p < 0.001); Mediterranean diet adherence (β = 0.09, p < 0.048) was associated with better physical health, while higher physical activity (β = − 0.14, p = 0.001) and being master’s students (β = − 0.12, p < 0.01) were predictors of better mental health. Even in a sample of highly active and good sleeper students, physical activity and sleep quality appear as critical factors in determining physical and mental health, underlying the necessity of interventions for university students’ lifestyles.