A cross-sectional study was conducted to investigate the weight status
and the relationship of infant-feeding variables, birthweight and birth
order with BMI in a group of Iranian children. Five hundred and eleven
students of both sexes at the first grade in elementary schools (aged 7
years) were recruited randomly from all 19 educational districts of
Tehran. Weights and heights of children and their mothers were
measured. Data on breastfeeding (BF), formula-feeding, the timing of
introduction of complementary foods (CF), birthweight, and birth order
were collected from the mothers. The 2007 WHO reference value was used
for determining child's weight status. Regression analysis in single
and a 2-level linear regression models was used for examining the
independent relationships of infant-feeding variables , birthweight and
birth order with childhood BMI. The prevalence of underweight and
overweight in this group of children was 7.6% and 19.7%, respectively.
Total time of BF and duration of exclusive BF were not associated with
childhood BMI. The timing of introduction of CF was inversely related
to childhood BMI after controlling for other variables (β:-0.34;
95% CI:-0.58,-0.10). Children with an early introduction of CF had
significantly higher mean BMI (p for linear trend=0.012). Birth order
and birthweight were related to childhood BMI significantly. These data
suggest that overweight and obesity are nutritional problems among 7
years old Teharani children. The timing of introduction of CF, birth
order, and birthweight were independent predictors of childhood BMI.
Neither total time of BF nor duration of exclusive breastfeeding was
associated with adiposity in children