<b><i>Introduction:</i></b> A rational way of nourishment, combined with adequate physical activity, are the basic components of maintaining proper body condition. <b><i>Objective:</i></b> The aim of the study was to evaluate nutritional status among children and adolescents with different levels of physical activity. <b><i>Methods:</i></b> The study group consisted of 1,013 students of both genders aged between 7 and 18 years attending elementary and post-primary schools (general and sports profile) in Siemianowice Slaskie. <b><i>Results:</i></b> The crude body mass index (BMI) values ranged from 12.78 to 35.3. Body mass within the limits of arbitrary standard referred to 70% of the examined group, overweight or obesity was found in over 25%. Percentage of body fat (FATP) values ranged from 5.7 to 45.2%. <b><i>Conclusions:</i></b> A significant number of children and adolescents were overweight or obese based on BMI categories and FATP values. Overweight and obesity were most common among younger children, particularly boys. Higher torso FATP levels were more common among sports-oriented class students. BMI is not a good tool for the determination of the nutritional status of children and adolescents, while the bioelectric impedance method enables one to conduct a precise analysis of adipose tissue content and location. Sports-oriented elementary school students from the study group were characterized by higher FATP values.