Introduction and objective:
Sleep plays a key role in maintaining physical and mental health. Its adequate length and quality affect hormonal regulation and metabolism. Sleep deficiency can increase the risk of diabetes, metabolic disorders, or obesity. Sleep is affected by, among other factors, physical activity, diet, light exposure, and alcohol consumption. The aim of the study is to evaluate the relationship between sleep duration and the selected aspects of lifestyle and health indicators among the academic community of the Silesian Medical University, with particular emphasis on body mass index (BMI), level of physical activity, frequency of snacking, exposure to screen light, and alcohol consumption.

Material and methods:
The study included 667 subjects: 396 students and 271 employees of the Silesian Medical University. A standardized KomPAN questionnaire, made available online, was used. Data were statistically analyzed for relationships between sleep and health indicators and health behaviours.

Results:
It was found that 63% of respondents had a normal weight. Sleep ≥9 hours was more often declared on weekends (32%). There was a statistically significant relationship between sleep duration on weekends and BMI (p = 0.047), but not on weekdays. Most subjects showed low physical activity during the week, although an increased physical activity on weekends. The percentage of those consuming sugary and salty snacks and spending long hours in front of screens was also high. Alcohol was mainly consumed occasionally.

Conclusions:
Sleep length on days off shows a relationship with body weight. The results suggest an impact of sleep on lifestyle, although some of the relationships require further, more controlled studies. Education on sleep hygiene and its impact on metabolic health and general well-being should be promoted.