A testösszetétel életkori és nemi mintázatának becslése az antropometriai módszerek és a bioelektromos impedancia analízis közötti összefüggések alapján

The present dissertation has been designed to predict body comp osition through a continuously expanding method in Hungary, namely, bioelectrical impedance analysis (BIA) . A limiting factor of the method is that the regressions of body fat content from the primarily measured impedance were validated for an unknown popu lation, therefore their use is not justified in other populations. Our goal was to develop regression equation s valid for the Hungarian population by us ing the sensor resistance data and anthropometric data in close correlation with body fat content, depe ndent of gender, age and maturity level; to be able to reliably predict body fat content between the ages of 10 – 18. The study sample was comprised of the subsample of the 1.5% randomized representative sample of young people between the ages of 10 – 18 of th e 2 nd Hungarian National Growth Stu dy (2003 – 2006 ) . The necessity to develop the new regression prediction equations is shown by the fact that the difference between the body fat content predicted by the BIA device and the reference method ( Drinkwater – Ross anthropometric fractionation method ) was significant in both gender s , in the majority of examined age ranges . Correcting the measurement results of the bioelectrical impedance analysis with the use of the new regression equations, the body fat content of Hungarian children between the ages of 10 – 18 can be predicted more precisely: the difference between the median values of the predicted absolute body fat content and the Drinkwater – Ross method barely exceeds 0.5 kg, meaning less than 2%. The difference exp ressed in percentages of the Drinkwater – Ross type prediction is on the average 1 – 4% in both genders for the studied age interval