Age, sex, ethnicity, body composition, and resting energy expenditure of obese African American and white children and adolescents.
BACKGROUND
African Americans may have a lower resting energy expenditure (REE) than do whites, although the data are limited for obese children and adolescents and for boys. Differences in bone density and trunk lean body mass may account for some of these measured differences in REE.


OBJECTIVE
We assessed the REE and body composition of obese African American and white children and adolescents.


METHODS
Obese, 5-17-y-old children and adolescents were evaluated (n = 203). Body composition was assessed by dual-energy X-ray absorptiometry. REE was measured by open-circuit calorimetry. African American and white children were compared. The relation between REE and the independent variables (age, sex, ethnic group, fat mass, and fat-free mass or lean tissue mass) was assessed.


RESULTS
Of those evaluated, 66% were girls and 34% were African American. Age, sex, pubertal status, and body composition did not differ significantly by ethnic group. All the independent variables were significantly associated with REE. Using lean tissue mass to account for differences in bone density did not significantly alter the results. REE decreased with age and was lower in the girls than in the boys and in the African Americans than in the whites. When trunk fat-free mass was included in the model in place of whole-body fat-free mass, the ethnic difference in REE decreased.


CONCLUSIONS
Adjustment for trunk lean tissue mass partially explains the lower REE of obese African American children and adolescents. The lower relative REE of older obese children suggests the importance of early intervention in the prevention of childhood obesity. The lower REE of girls and of African Americans may contribute to the difficulty in weight management in these groups.
Tershakovec
Andrew M
AM
Division of Gastroenterology and Nutrition, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA. tersh@mail.med.upenn.edu
Kuppler
Kerri M
KM
Zemel
Babette
B
Stallings
Virginia A
VA
D000293:Adolescent; D001741:Black or African American; D000375:Aging / Q000502:physiology*; D044383:Black People; D001823:Body Composition; D002648:Child; D002675:Child, Preschool; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000201:enzymology* / Q000473:pathology* / Q000503:physiopathology; D012146:Rest; D012727:Sex Characteristics; D044465:White People