Height and adiposity among children.
OBJECTIVE
Although BMI (kilograms per meter squared) is widely used as a surrogate measure of adiposity, it is moderately associated (r approximately 0.3) with height among children. We examined whether the resulting preferential classification of taller children as overweight, based on a BMI > or = 95th percentile, is appropriate.


METHODS
We assessed the cross-sectional relation of height among 5- to 18-year-old subjects (n = 1180) to levels of BMI, the sum of 10 skinfold thicknesses, and percentage body fat as determined by DXA.


RESULTS
The prevalence of a BMI level > or = 95th percentile was substantially higher among 5- to 11-year-old subjects who were relatively tall for their age than among shorter children. Among 5- to 8-year-old boys, for example, each SD increase in height-for-age was associated with a 4.6-fold increase in the prevalence of overweight (p < 0.001). Height not only was associated with BMI but also showed similar correlations with the skinfold sum and with percentage body fat; furthermore, the magnitudes of these associations decreased with age. We also found that the association between percentage body fat and BMI (r = 0.85 to 0.90) was close to the maximum correlation that can be achieved by any weight-height index.


CONCLUSIONS
The use of BMI, which preferentially classifies taller young children as overweight, is appropriate because height and adiposity are correlated before the age of 12 years.
Freedman
David S
DS
Division of Nutrition and Physical Activity, Centers for Disease Control and Prevention, Mailstop K-26, 4770 Buford Highway, Atlanta, GA 30341-3717, USA. DFreedman@CDC.gov
Thornton
John C
JC
Mei
Zuguo
Z
Wang
Jack
J
Dietz
William H
WH
Pierson
Richard N
RN
Horlick
Mary
M
D015502:Absorptiometry, Photon; D000273:Adipose Tissue; D000293:Adolescent; D001823:Body Composition; D001827:Body Height; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D012885:Skinfold Thickness; D011795:Surveys and Questionnaires