Energy expenditure and substrate oxidation predict changes in body fat in children.
BACKGROUND
The hypothesis that alterations in energy metabolism predict body fat gain is controversial.


OBJECTIVE
The aim of this study was to determine which components of energy metabolism were most important in predicting fat gain in children aged 10.8 +/- 0.6 y.


METHODS
A 2-y longitudinal study to examine whether components of energy metabolism are predictors of body fat gain was conducted in 114 preadolescent African American and white children aged 9-11 y by measuring total daily energy expenditure on the basis of doubly labeled water (DLW), resting metabolic rate, the thermic effect of food, energy expended in physical activity, and substrate oxidation after a meal. The primary endpoint was the 2-y change in percentage body fat (%BF).


RESULTS
Individual variables of energy metabolism predicted up to 7% of the variance in changes in %BF over the 2-y interval in the whole group. Predictors of change in body fatness tended to be sex and race specific. Protein oxidation during a test meal explained a significant portion of the variance in change in %BF in the overall group and in nearly all of the subgroups. Multivariate prediction models accounted for 10-41% of the variance in change in %BF. Tanner stage at 2-y follow-up was highly predictive of change in body fatness and improved the overall prediction, accounting for 24-62% of the variance in change in %BF in those groups in which Tanner entered the model.


CONCLUSIONS
This study provides evidence that total daily energy expenditure, resting metabolic rate, substrate oxidation, and total energy intake are predictors of gain in body fatness during late childhood in boys and girls.
DeLany
James P
JP
Pennington Biomedical Research Center, Baton Rouge, LA, USA. delanyj@dom.pitt.edu
Bray
George A
GA
Harsha
David W
DW
Volaufova
Julia
J
D000273:Adipose Tissue; D001741:Black or African American; D001481:Basal Metabolism; D002648:Child; D017666:Deuterium Oxide; D004044:Dietary Proteins / Q000378:metabolism; D002149:Energy Intake; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D015999:Multivariate Analysis; D010084:Oxidation-Reduction; D011237:Predictive Value of Tests; D011627:Puberty; D022722:Thermogenesis; D015430:Weight Gain; D044465:White People
D004044:Dietary Proteins; D017666:Deuterium Oxide