Background: The prevalence of obesity and overweight in children and adolescents is increasing worldâwide. Obesity in children and adolescents is a major risk factor for diabetes, heart diseases, hypertension, and cancer in adulthood. Aim: The aim of the study was to compare the nutritional status and foodâstuffs among highâschool girls in Arak, Iran, in matter of body mass index (BMI) and associated factors. Subjects and Methods: A crossâsectional survey of a representative sample of 278 adolescents was conducted in six randomly chosen highâschools. Height and weight of students were collected using standard methods and the BMI calculated and BMI percentiles of these girls are compared with the Center of Disease Control and Prevention (CDC) reference data. The 5th, 8th, and 95th percentiles of the CDC were adopted as cutâoff points for underweight, overweight and obese girls, respectively. Data were analyzed using SPSS by analysis of variance and Chiâsquare tests. Results: On the basis of CDC, the overall prevalence rates of underweight, overweight, and obesity were estimated 10.1% (28/278), 12.9% (36/278), and 1.4% (4/278), respectively. There was no significant difference between nutritional knowledge scores and the rate of physical activities in various groups. The mean age at menarche was significantly higher among the obese girls (P = 0.02). Consumption of iceâcream and chocolate was significantly higher in the obese girls group (P = 0.03). Conclusion: According to the present study, the prevalence of overweight and obesity in highâschool girls of Arak is lower than that of many other parts of Iran and some neighboring countries, which are at the highârisk of overweight and obesity. This study warrants the necessity of paying attention to promote healthy lifeâstyle and weight control. The earlier age of menarche is alarming.