Fat Mass Index (FMI) comparing to Body Mass Index (BMI) in the determination of obesity in preschool children

Based on BMI prevalence of obesity and overweight among preschool children were 5.1 and 9.8, respectively; moreover the prevalence of overweight and obesity was higher in boys than girls. The difference between two sexes was not significant (p=0.211, p=0.834). About 46% of really obese children and 4% of the non-obese children, who were not obese according to FMI, were diagnosed as obese by BMI. Moreover, using FMI as a real measure of obesity, sensitivity and specificity of BMI 90 percentile appeared to be 73% and 97.4%, respectively. Despite having high specificity, BMI had low sensitivity and may have low efficiency in diagnosing childhood obesity. It seems that comparing to BMI; FMI is a better indicator to determine obesity in children. However, the lack of precise standard references for FMI makes further studies in this area necessary.