Characteristics of percentile value changes in body composition of children and adolescents aged 7 to 18 in Beijing

Abstract

Objective To analyze the trend of percentile changes in body composition among children and adolescents aged 7 to 18 by gender and age, and to provide a scientific basis for reference value.

Methods A stratified cluster random sampling method was used to select 1 585 children and adolescents from September to December 2020. Use the GAMLSS to estimate the P ₂₅, P ₅₀ and P ₇₅ percentile value of gender, age-specific body fat percentage (BF%), fat mass index (FMI) and fat-free mass (FFM).

Results In different age groups, body fat percentage of boys with normal nutritional status peaked at around 10-year-old, among them, body fat percentage of 10-year-old P ₂₅, P ₅₀ and P ₇₅ were 22.2%, 26.1% and 30.1%, respectively. Body fat percentage of obese boys was at a high level. Among girls, body fat percentage under different nutritional status did not change. With the increase of age, fat mass index plateaued slightly in normal and overweight boys. However, in obese boys, with the increase of age, FMI gradually increased with the increase of percentile, while the value of FMI gradually decreased in girls. Whether in boys or girls, with the increase of age, fat-free mass index shows an increasing trend, and boys increase faster.

Conclusion Under different nutritional status, there are differences in the percentile value of body fat percentage, fat mass index and fat-free mass by gender and age, which can provide a scientific basis for reference value of body composition in children and adolescents.

Abstract

【摘要】 目的 分析 7~18 岁儿童青少年不同性别、年龄体成分百分位值变化趋势特点, 为制定百分位参考值提供科学依 据。 方法 2020 年 9一12 月采用分层整群随机抽样的方法, 共纳入北京市 7~18 岁儿童青少年 1 585 人。利用 GAMLSS 法 估计性别、年龄别的体脂率 (BF%)、脂肪质量指数 (FMI) 和瘦体重 (FFM) 的 P ₂₅、 P ₅₀ 和 P ₇₅。 结果 在不同年龄组中, 营养 状况正常的男生体脂率在 10 岁左右出现峰值, 其中 10 岁儿童青少年体脂率 P ₂₅、 P ₅₀ 和 P ₇₅ 分别为 22.2%, 26.1% 和 30.1%, 肥胖男生的体脂率均处于较高的水平;而女生不同营养状况下不同年龄组的体脂率变化不明显。营养状况正常和超重男 生中, 随着年龄的增加, FMI 处于平缓水平;但在肥胖的男生中, 随着年龄的增加, FMI 随着百分位的增高变化值逐渐增大, 而女生逐渐减少。无论是在男生还是女生中, 随着年龄的增加, FFM 呈现增长的趋势, 且男生增长的速度更快。 结论 在 不同营养状况下, 不同性别和年龄儿童青少年的体脂率、脂肪质量指数和瘦体重的百分位值存在一定的差异, 在一定程度 上可为制定儿童青少年体成分百分位参考值提供依据。