著者

秋原 悠 小田 俊明 山本 忠志 曽我部 晋哉

出版者

Japan Society of Human Growth and Development

雑誌

発育発達研究 (ISSN:13408682)

巻号頁・発行日

vol.2020, no.89, pp.22-32, 2020 (Released:2020-12-25)

参考文献数

25

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The purpose of this study was to clarify the characteristics of body composition of Japanese elementary and junior high school students. In this study, body composition was measured using a body composition analyzer (Inbody470).In this method, body composition take as a 4-components model (total body water/protein/mineral/body fat mass), and the subdivided data can be easily analyzed. Subjects that were included in this study total 791 students (Boys: 373, Girls: 418) from the 1st grade of elementary school to the 3rd grade of junior high school.As a result of the analysis, both the boys and girls height and weight gradually increased year by year. The amount of fat-free mass also increased, but body fat mass decreased in boys after the 6th grade of elementary school. For the girls, it increased year by year. The results showed the differences for each gender in all components since junior high school. In particular, there was a marked difference in the 3rd grade of junior high school (total body water: p < 0.001, protein: p < 0.001, mineral: p < 0.001, body fat mass: p < 0.001). In the 4-components, regardless of the age difference in junior high school students, only protein significantly increased in boys (p < 0.05). For the girls, total body water (p < 0.001), protein (p < 0.001), and minerals (p < 0.01) were significantly decreased, and body fat percentage (p < 0.001) was significantly increased.This study clarified the gender differences and age differences of the 4 components of the body. From these results, the deterioration of the body components especially for junior high school student girls were concerned, and the necessity of taking countermeasures in exercise habits and lifestyle habits were indicated.