Background: For the first time, not only in Iran but also in the Eastern Mediterranean region, we report the prevalence of underweight and overweight among all children at school entry.

Methods: The current study was part of the national screening survey of all children at school entry that was conducted in all 31 provinces of Iran in 2007. Body mass index (BMI) cut-off points provided by the US Centers for Disease Control and Prevention were used.

Results: This cross-sectional national study was performed among 899 035 children (48.8% girls and 51.2% boys); 76.7% of them lived in urban areas. Overall, 12.7% of the children had a BMI below the age- and gender-specific 5th percentile, and with the highest prevalence in the southern provinces. In addition, 17.0% of the children had high BMI levels, i.e., 13.5% were overweight and 3.5% were obese, with the highest prevalence in the capital city as well as in the western and northwestern provinces.

Conclusions: Until a few years ago, childhood undernutrition has been the major nutritional problem in our community and still is the focus of nutritional policies and related medical education curriculum; however the higher prevalence of overweight other than underweight obtained in the current national survey is alarming and confirms the importance of considering childhood overweight as a health priority. This should be taken into account for all Middle Eastern countries that are expected to bear one of the world's greatest increases in the burden of chronic diseases notably diabetes in the next two decades.

Key words: Iran; overweight; pre-schoolers; underweight

                  World J Pediatr 2010;6(3):223-227