Qom University of Medical Sciences Journal

Background and Objectives: The prevalence of childhood overweight and obesity has been increasingly growing in many societies. The present study aimed to determine body mass index (BMI) in primary school boys and girls in Tabriz city.

Methods: This descriptive cross-sectional study was conducted on 857 primary school students of Tabriz city in 2012-2013. First, BMI of each person was calculated, and according to the NCHS standard curves, the values below the 5^th percentile were considered as malnutrition and underweight, between the 85^th-95^th percentiles as overweight, and equal to or above the 95^th percentile as obesity. Data were analyzed by one-sample t-test and t-test. The significance level was considered to be p<0.05.

Results: According to the BMI data, the frequency of underweight, overweight, and obesity in the male students, were 20.9, 5.5, and 3.1%, and in female students were 18.8, 9.7, 0.9%, and in the total number of students were 20.1, 7.4, and 2.1%, respectively. Compared to the 50^th percentile, the mean BMI in male students in the age group of 9 years was higher (p<0.01) and in the age group of 6 years was lower (p<0.05). This comparison in the female students indicated higher mean BMI in the age groups of 7, 9, 10, and 11 years compared to the 50^th percentile (p<0.05). The frequency of overweight among female students (9.7%) was higher than male students (5.5%). However, the frequency of obesity in the male students was approximately 3.5 times higher than female students (p<0.05).

Conclusion: Given the existence of both malnutrition states of underweight and obesity in the students and also the significant effect of childhood body weight on chronic disorders in adulthood, proper nutrition planning is necessary at the school level.