Infants Body Mass Index Reference Curves for Iran

Abstract

Background: The body mass index, defined as weight/height2, is often used to monitor childhood obesity. The BMI offers a reasonable measure of fatness in children. This study was designed to document the distribution of body mass index (BMI) in healthy south Iranian infants and present local BMI reference values. Methods: A cohort of 317 healthy full term neonates (153 boys and 164 girls) were selected randomly from all maternity hospitals of Shiraz (southern Iran) and were followed for two years from their birth. BMI centiles based on the original height and weight data were derived using the HRY method. Results: BMI rised in the first six months of infants life, followed by a mild fall up to the age of 21 months, then stayed almost stable. Age related cut off points were assigned to the 5th centile for thinness, 85th centile for overweight and 95th centile for obesity, which were appropriate for classifying the degree of fatness. Girls BMI centiles lie below boys. Conclusions: Shiraz infants were relatively free of obesity. BMI centiles are suitable tools to monitor infantile obesity and serve as a baseline. However, they should be studied with other obesity indices such as weight-for-height and scaled weight by height.
Keywords: Body Mass Index, Obesity, Overweight, Percentile, Preschool Children, Developing Countries, Infants.