BODY-COMPOSITION, RESTING METABOLIC-RATE, AND ENERGY-REQUIREMENTS OF SHORT-STATURE AND NORMAL-STATURE, LOW-INCOME GUATEMALAN CHILDREN

We examined body composition using bioelectrical impedance analysis an d isotope dilution (O-18 and H-2), resting metabolic rate (RMR) by ind irect calorimetry, and total energy expenditure (TEE) by doubly labele d water in 15 short-stature (height-for-age less than or equal to -1.5 SD) and 15 normal-stature (height-for-age > -1.5 SD) Guatemalan child ren aged 4-6 y. Although, in absolute terms significant group differen ces were found in fat-free mass (FFM), fat mass, and total body water (TBW), there were no significant differences in fat mass and TBW after adjustment for FFM. RMR of the short-stature children (3791 +/- 376 k J/d) was not significantly different from that of normal-stature child ren (4038 +/- 531 kJ/d), and the regression between RMR and FFM was al so not significantly different between groups. TEE was not significant ly different in short-stature (4753 +/- 761 kJ/d) compared with normal -stature children (5304 +/- 1020 kJ/d); the regression between TEE and FFM was not significantly different between the two groups. There wer e no significant group differences in RMR and TEE after adjustment for FFM. FFM was the strongest predictor of TEE, but could only explain 2 9% of the variance. We conclude that 1) the lower TBW and fat mass in the short-stature group is proportional to their lower FFM, 2) there i s no significant difference in either RMR or TEE between short- and no rmal-stature children, and 3) TEE is highly variable among these child ren and cannot be explained by differences in body size alone.