Body composition of Japanese children

Abstract

There is limited information about total and regional body composition in children at the organ tissue level. The purpose of this review is to take note of the current body of knowledge regarding body composition research in Japanese children on the basis of recent data centering on fat mass and skeletal muscle (SM) mass. According to the author’s recent findings of fat mass, 1) the value of % fat in overweight boys and girls was over 35% using DXA measurement; 2) about 50% of the difference in whole body fat mass, between overweight and normal weight children, may be attributable to incremental increases in trunk fat mass in both boys and girls; and 3) equations using skinfold calipers and ultrasound seem to be more useful field methods in estimating fat mass specifically for children at the present time. Moreover, the author’s new studies of SM mass indicate that 1) whole body SM mass dramatically increases from prepubertal (9.2 kg for boys, 10.8 kg for girls) to adolescent stages (20.0 kg for boys, 14.6 kg for girls), which is similar to adults (22.3 kg for males, 13.5 kg for females); 2) the increase in SM mass, during each growth stage, seems to be fairly constant on the extremities and trunk area in both boys and girls; and 3) the adult ultrasound-derived prediction equations for SM mass are applicable for adolescents near 14 years of age, but are not valid for prepubertal children. Future research will involve the development of equations for estimating fat mass and SM mass for prepubertal children and adolescents.