Objective We aimed to investigate the association of increased smartphone screen time with insomnia, bedtime procrastination, depression, anxiety, body mass index (BMI), and physical activity during the coronavirus disease of 2019 (COVID-19) pandemic.Methods An online survey was performed for university students from all regions of Lebanon during the lockdown. The survey included questionnaires about smartphone screen time, diet, physical activity, psychological symptoms, and bedtime procrastination. We defined 6 hours of smartphone use as critical based on a survey done in United States.Results Among female students, smartphone use duration, physical activity levels, BMI, depression, anxiety, and insomnia severity were significantly higher than in male. When we stratified participants based on 6 hours of smartphone use, females, unhealthy food consumption, insomnia, anxiety, depression, and bedtime procrastination were significantly higher in the group with ≥6 hours of smartphone use. When we divided based on 7 hours, physical activity and body weight also differed between the two groups. Logistic regression analysis revealed that female, overweight, insomnia, and bedtime procrastination were significant predictors of a phone screen time of 7 hours.Conclusion Our findings suggest that adults should be more cautious and responsible when using smartphones and be more concerned about the health-related risks.