Prevalence of Obesity in the First Grade Primary School Children in Mehriz, Iran, based on Different References of Body Mass Index

Obesity is a metabolic disorder that its prevalence in various age groups, including children increased in recent decades. Obesity in children can be diagnosed using Iranian, CDC, WHO and IOTF references. The environmental and racial factors can influence on anthropometric indices, so the reference body mass index can also be different in societies. Therefore, this study aims to determine the prevalence of obesity in children entering primary schools in Mehriz and compare it with different body mass index references.

This cross-sectional descriptive-analytical study was done on 1209 children entering primary schools of Mehriz city. The gender, weight and height were recorded and then the students' BMI was calculated. The determination of obesity as a percentile above 95 was examined based on four reference sources: Iranian, WHO, CDC and IOTF.

According to the findings of this study, the prevalence of obesity in children entering primary schools in Mehriz city based on four references: WHO, CDC, IOTF, and Iranian were respectively 6.2%, 6.9%, 3.8%, And 6.9%. Comparison of prevalence based on different references showed that the WHO and CDC index agreed with the Iranian reference. But the agreement of the IOTF index was not statistically significant.

The prevalence of obesity in children entering primary schools in Mehriz city according to Iranian and WHO authorities were completely equal and other references estimated the prevalence of obesity to different rates. Because obesity has a very complex relationship with environmental, genetic, cultural, and lifestyle factors, it is recommended that each country use the national body mass index reference or WHO reference to determine obesity.