Background and Objectives: Several studies have so far been carried out to determine the prevalence of overweight and obesity among Iranian children but few studies have investigated the relationship between eating habits, socio-demographic differentials and obesity in these children. So, this study tried to assess the body weight status among the urban high school boy students of Urmia, Iran.

Materials and Methods: In this cross-sectional study, we measured weight, height and BMI of 1026 boy students with an age range of 15 to 19 years by multi-stage sampling. Then a questionnaire was completed based on their dietary habits and behaviors related to their physical activity. Overweight and obesity were defined based upon the World Health Organization’s growth charts. Statistical analysis was fulfilled by estimating absolute and relative frequencies.

Results: Underweight prevalence in the studied population was 9.84% (95% CI: 8.49%-10.72%). The prevalence of overweight and obesity among the studied students was 12.77% (95% CI: 11.89%-13.3%), and 5.07% (95% CI: 4.5%-5.9%), respectively. Factors significantly correlated with the participants' body weight were the frequency of energy dense foods intake during a week (P<0.001), duration of computer use per day (P<0.01), and the kind of their schools (P<0.05). No significant association was found between other studied dietary variables (such as the time spent for eating over 24-hours, and breakfast eating times per week) and overweight/obesity.

Conclusions: In the present study, we found that two changeable parameters (i.e. the number of times for intake of energy dense foods during a week, and working with computers) could influence the 15-19 years old school boys' body weight in the study region.

Keywords: Prevalence, Underweight, Overweight, Obesity, High school boys