Introduction:
Overweight and obesity affect an increasing number of children and adolescents in Poland. This excessive body weight usually coexists with sleep disorders and other afflictions, which is worrisome.

Objective:
The aim of the study was to assess the prevalence of overweight, obesity, and sleep disorders among adolescents and demonstrate their relationships.

Material and methods:
The study included 1,002 students. Nutritional habits and subjective assessment of sleep were evaluated with the author’s survey; daytime sleepiness and sleep quality were assessed with Epworth Sleepiness Scale (ESS) and Sleep Quality Scale (SQS). Statistical calculations were performed with the STATISTICA 12.0 programme.

Results:
24.7% of adolescents suffered from overweight or obesity, 38% reported sleep problems in subjective assessment, 10.5% exhibited excessive daytime sleepiness, determined by ESS, and 14.3% had impaired quality of sleep as determined by SQS. Gender affected all the discussed problems. Type of school affected all the above, except for daytime sleepiness. In the group with overweight and obesity, 46.6% of individuals reported sleep problems in subjective assessment. About 59.1% of adolescents reported chronic fatigue. Reduced concentration and difficulties in learning were reported in 36.3% of all students, and in 46% of students with overweight and obesity.

Conclusions:
The problem of excess body weight is a very alarming phenomenon since it affects almost 1/4 of the students. Almost half of the students with overweight and obesity reported sleep problems, which is strongly correlated with the type of school. Furthermore, excess body weight influenced the prevalence of reduced concentration and learning difficulties among adolescents.