Secular trends in the national prevalence of overweight and obesity during 2007-2009 in 6-year-old Iranian children.

Background: This study aimed to determine the secular trends in the national prevalence of overweight and obesity among 6-year-old Iranian children, and to compare the results in Northern, Central and Southern parts of the country.

Methods: The data were collected as part of a routine and mandatory national screening program on children entering elementary schools in 2007, 2008 and 2009.

Results: The study population comprised 2,600,065 children including 862,433 in 2007, 782,244 in 2008 and 955,388 in 2009.