The percentage of children and adolescents with overweight and obesity problem is higher inPolandthan in other European countries, and for this reason, this group ought to be covered by educational actions in order for them to cause changes in their current lifestyle. The aim of the study was to present the scale of overweight and obesity, and knowledge of the principles of nutrition, dietary behaviors and physical activity in daily life of middle school students from Lubartów. The study was conducted on a group of 100 Lubartów students in grades I-III, aged 13-15 years. The applied method of research was diagnostic survey and authorial interview questionnaire was the main tool. 11.3% of researched girls were found to be overweight and obesity was confirmed for 7.5% of all respondents. Most overweight boys and boys with obesity were 15 years of age. Respondents declared knowledge of the principles of nutrition, more frequently girls with abnormal body weight than boys. Youngsters tend to eat what they like, wile they rarely draw attention to the fact whether the product is healthy. Five meals a day were consumed by a total of 30% of students and 44.0% of the students always ate breakfast. It has been shown that 59.1% of adolescents with abnormal body weight were dissatisfied with their performance. Based on the results the following conclusions were drawn up: 1 Obesity occurs in 7.50% of girls and 8.50% of boys of the middle school in Lubartów. 2 Youth knows the principles of nutrition, but does not always select the healthy products, eats inappropriately, eats snacks between meals. 3 Middle school students rarely eat vegetables, fruits and dairy products. 4 Hereditary phenomenon of obesity was observed in subjects with abnormal body weight. 5 Youth is not physically active, they spend their free time in a passive way. 6 Overweight / obesity determine a negative social assessment by peers.