Abstract
The sample of 234 7th and 8th grade boys, attending elementary schools located within the town of Sombor, was subject to body composition assessment by using the indices of body composition (body mass index) and methods by Mateika. Based on the estimated fat mass value, using the method by Mateika, the subjects were categorized by age, as recommended by McCarthy et al. Based on indices of body composition, also depending on the age, they were classifi ed into categories according to the International Obesity Task Force (IOTF) standards, determined by Cole et al. There was a significant difference in the number of subjects classified in the category of the overweight and those classifi ed in the category of the obese in favor of greater sensitivity of the method by Mateika. Considering that for both categories medical monitoring is recommended, the results of the research give priority to the assessment of body composition by the method by Mateika despite much more complex methodology.