STANDARDS FOR TOTAL-BODY FAT AND FAT-FREE MASS IN INFANTS

Data on body composition in conjunction with reference centiles are he lpful in identifying the severity of growth and nutritional disorders in infancy and for evaluating the adequacy of treatment given during t his important period of rapid growth. Total body fat (TBF) and fat-fre e mass (FFM) were estimated from total body electrical conductivity (T BEC) measurements in 423 healthy term Caucasian infants, aged 14-379 d ays. Cross sectional age, weight, and length related centile standards are presented for TBF and FFM. Gentiles were calculated using Altman' s method, based on polynomial regression and modelling of the residual variation. The TBF percentage steeply increased during the first half year of life, and slowly declined beyond this age. Various simple TBE C derived anthropometric prediction equations for TBF and FFM are avai lable to be used in conjunction with these standards. Regression equat ions for the P50 and the residual SD, depending on age, weight, or len gth, are provided for constructing centile charts and calculating stan dard deviation scores.