Author
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Ellis, Kenneth |
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Submitted to: The American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/26/1997 Publication Date: N/A Citation: N/A Interpretive Summary: We wanted to determine body composition values for young growing males to establish findings of general use in future research studies by investigators. We studied nearly 300 white, black and Hispanic males, 3 to 18 years of age, using a state-of-the-art technique called dual-energy X-ray absorptiometry to examine their individual body composition. We found that bone mineral content and lean tissue mass were higher in black than white males, but white and Hispanic males did not differ in bone or lean mass. The Hispanics had more body fat than the whites or blacks, while the blacks, as a group, had less body fat than the white males. We recommend that in future studies of young males, investigators should use reference values of total body composition that are specific to individual ethnic groups, because of the differences between groups that we were able to demonstrate here. Technical Abstract: The study objective was to establish the range of total body composition values for a young multiethnic healthy male population (aged 3-18y) by using dual-energy x-ray absorptiometry (DXA). Results for 297 males in three ethnic groups [European American (white), n= 145; African American (black), n= 78; and Mexican American (Hispanic), n= 74] are reported. Changes in the bone mineral content (BMC), lean tissue mass(LTM), fat mass and percentage fat are presented as functions of age. Analysis of variance with age, weight, and height as covariates was used to evaluate differences among the three ethnic groups. BMC and LTM were higher in the black males than the white males, but no difference in BMC or LTM was evident for the white vs Hispanic groups. The relation between total body BMC and LTM was linear (r=0.985, P<0.0001) and independent of age or ethnic classification. The Hispanic males had higher body fat values than the white group, whereas sthe black males generally had lower values. When adjusted for body size, the Hispanic males continued to have significantly higher body fat and percentage fat than the white or black males in this study. Ethnic- specific equations for the prediction of body composition as a function of age, weight, and height were derived. The results for the white males in the present study were compared with DXA-derived reference data for young white males reported in other countries. We conclude that reference values of total body composition for young healthy males need to be ethnic- specific. |
