7～15岁体重正常儿童身体成分变化分析

Changes in Body Composition of Normal-weight Children Aged 7-15 Years

目的 分析7～15岁体重正常儿童身体成分及其随年龄变化的特点和性别差异，为儿童生长发育的研究提供依据。方法 在北京市选择2所中小学7～15岁体重正常儿童180名，每性别、年龄组约10名，采用DEXA测定身体成分。结果 7～13岁儿童机体脂肪组织（FM）及全身脂肪百分比随年龄增加而增加，13岁以后有所下降，女生高于男生，去脂肪组织（FFM）随年龄增加而增加；四肢和躯干脂肪占全身脂肪百分比随年龄增长而接近，男生7～13岁、女生7～12岁四肢脂肪组织占全身脂肪组织百分比大于躯干，但男生14～15岁、女生13～15岁小于躯干。结论 青春期前后儿童脂肪组织含量及分布随年龄而变化，且男女差异明显；男性脂肪向心性分布加速期在12岁，女性在10岁。

Objective To analyze body composition, characters of its changes with age and sexual difference of normal-weight children aged 7 - 15 years, and to provide evidence for children＇s growth and development. Methods From a primary and a secondary schools, For each sexual and age group of 7 - 15 years old, about 10 normal-weight children （ 180 subjects totally） were selected to receive body composition measurement by dual-energy x-ray absorption（ DEXA）. Results Fat mass and body fat percentage increased with age from 7 to 13 years old and decreased after 13 years old. Girl＇ s were higher than boy＇s. Fat-free mass increased with age. Percentages of llmb and trunk fat accounting for body fat approached to each other with age. Percentages of limb fat accounting for body fat was higher than that of trunk fat for boys aged 7 - 13 years and girls aged 7 - 12 years, while lower than that of trunk fat for boys aged 14 - 15 years and girls aged 13 - 15 years. Conclusion Quantity and distribution of fat mass change with age around puberty, and the diversity is significant botween boys and girls. 12 and 10 years old are the accelerating phases for central distribution of fat for male and female respectively.