Some brown-hued breads are simply white bread with food coloring. But preliminary findings from a large-scale CNRC study suggest tempering enthusiasm with an understanding of the BMI's limitations. One out of six children whose BMI value was in the normal range was found to have an unhealthy level of body fat. Ellis compared calculated BMI values for an ethnically diverse group of 979 boys and girls, ages 3 to 18, to scientific measurements of their body fat. One is that every individual whose BMI is within the normal range has a normal amount of body fat.
Few people think that normal-weight kids can have unhealthy levels of body fat.
Yet, the DXA measurements of children with calculated BMI values between 18 and 20 showed body-fat percentages ranging from 10 to 40 percent. Body-fat levels over 30 percent are generally considered unhealthy in children over 3 years of age. There is also the risk of labeling one out of four children with a high BMI as at-risk or overweight when they actually have normal amounts of body fat. High levels of physical activity, early maturation, genetics and ethnicity can all contribute to a child having a high BMI but a healthy amount of body fat. It does not measure bone, fat or muscle.