A Study on Obesity of Junior High School Children by the Analysis of Skinfold Thickness

Measurements of physical size and the skinfold thickness of upper arm and back were performed on 2060 boys and 1895 girls of junior high schools in Numazu City. The results were as follows: (1) In boys, the mean skinfold thickness value of upper arm decreased slightly according to age, while increased in girls. (2) The mean skinfold thickness value of back increased according to age in either sex. The increase in girls was larger. (3) The mean skinfold thickness value of upper arm + back with all school grades was 14.8 ± 6.8mm in boys and 24.1 ±8.7mm in girls. The difference by age was very small in boys, while an apparently significant difference was observed in girls, comparing between 12-and 15-year-old girls. As for P50, (Pcrcentile 50) P75 and P95 of skinfold thickness of upper arm+back, the difference by age was also very small in boys. But they increased according to age in girls. Only P95 of 14-and 15-year-old children of either sex was almost similar. (4) Obesity screening was performed applying several methods as the increase rate over the standard weight of each height, Rohrer Index, skinfold thickness and Mori Index (the increase rate over the standard weight of each height x skinfold thickness). The selecting rate of obese children was almost similar in the increase rate over the standard weight of each height and skinfold thickness. (5) Muscular children could be omittd from obesity by applying Mori Index.