BODY-WATER, LEAN BODY AND FAT MASS OF HEALTHY-CHILDREN AS MEASURED BYDEUTERIUM-OXIDE DILUTION

Body composition of 165 healthy children was measured using the well-e stablished method of deuterium oxide ((H2O)-H-2) dilution. After distr ibution of an oral load of 2.0 ml (H2O/kg)-H-2 body weight body water was estimated from the (H2O)-H-2 concentration in urine. Lean body mas s was then calculated from body water using previously published age d ependent ratios of the water content of the lean body mass. Fat mass w as calculated as the difference of body weight and lean body mass. A g ood correlation was found between body water and body weight. Linear r egression revealed TBW = 0.589 BW + 0.728 (r = 0.99). Body water, lean body mass and fat mass were found to change with age. The fat content of the body increases during the first six months of life. It then de creases until four to five years then rising again until 15 years of a ge.