本文对中国少数民族23352例（男10070例,女13282例）的体成分进行了分析,以了解中国少数民族脂肪率、肌肉量的现状,探讨体成分随年龄增长的变化规律。研究发现,男性和女性总体上属于超重水平,还没有达到肥胖水平。与南方族群男性相比,北方阿尔泰语系族群的男性四肢脂肪率高、内脏脂肪等级高、水分率低。南方族群中,藏缅语族群、苗瑶语族群、壮侗语族群的四肢脂肪率、内脏脂肪等级、水分率相对接近;南亚语系族群与这3个南方族群差距较大。与南方族群女性相比,北方阿尔泰语系族群的女性躯干、四肢肌肉量大,骨骼重;南方4个族群女性躯干、四肢肌肉量较小,骨骼较轻,骨量、肌肉量彼此接近。随年龄增长,男性骨量下降,水分率增大;上肢脂肪率减小,躯干脂肪率增大,内脏脂肪等级增大,即脂肪向躯干集中,全身总体脂率增大;下肢肌肉量减少,躯干肌肉量下降,最终导致全身总肌肉量下降。随年龄增长,女性上肢的脂肪率和肌肉量没有明显变化,下肢的脂肪率下降,躯干脂肪率和内脏脂肪等级增大,总体脂率增大;躯干肌肉量下降,总肌肉量下降。男性推定骨量下降的节点是50岁,女性是60岁。男性总肌肉量下降的节点是40岁,女性是50岁。男性、女性身体水分率增加的节点都是60岁,内脏脂肪等级增加的节点都是30岁,总脂肪率下降的节点都是60岁,躯干脂肪率增加的节点都是30岁,躯干肌肉量下降的节点都是40岁。研究还发现,体脂率、内脏脂肪等级与血糖呈显著正相关。研究结果反映了中国少数民族从青年到老年的体成分变化的基本规律。

The bioelectrical impedance method was used to measure the body composition of 23352 adults (10070 males and 13282 females) from the minorities in China. This paper is to understand the current status of fat percentage and muscle mass in Chinese minorities, and to explore the changes in body composition with age. We found that males and females are generally overweighted, but not reached the level of obesity yet. Compared with the southern male ethnic groups, the males of northern Altaic languages ethnic groups have higher limb fat percentages, higher visceral fat levels and lower water percentages. Among the southern ethnic groups, the Tibeten-Burman languages ethnic groups, the Miao-Yao languages ethnic groups and the Zhuang-Dong languages ethnic groups have relatively close limb fat percentage, visceral fat level and water content. The South Asian languages ethnic groups has a large difference with these three southern ethnic groups. Compared with southern female ethnic groups, females from the northern Altaic languages ethnic groups have large torso and limb muscles and heavy bones. The female torso and limbs of the four southern ethnic groups have smaller muscle mass and lighter bones, which are close to each other. With age increases, male’s bone mass decreases, and water content increases, and upper extremity fat rate decreases, and trunk fat rate increases, and visceral fat levels increase, and fat concentrates in the trunk, and overall body fat rate increases. The muscle mass of the lower limbs of the male is reduced, and the muscle mass of the trunk is reduced, which ultimately leads to a decrease in the total muscle mass of the whole body. With age increases, the female’s fat rate and muscle mass of the upper extremities did not change significantly, the fat rate of the lower extremities decreased, the trunk fat rate and visceral fat level increased, the overall fat rate increased, the trunk muscle mass decreased, and the total muscle mass decreased. The cut-off point for male’s presumed decline in bone mass is 50 years old, and female is 60 years old. The cut-off point for a decline in total muscle mass in male is 40 years old, and female is 50 years old. The cut points for increasing the body moisture rate of males and females are all 60 years old, the cut points for increasing the visceral fat level are all 30 years old, the cut points for decreasing the total fat rate are all 60 years old, the cut points for increasing the body fat rate are 30 years old, and the cut-off points for torso muscle mass are 40 years old. We also found that body fat rate, visceral fat level and blood glucose levels were significantly positively correlated. The results of this paper basically reflect the basic laws of the changes in body composition from youth to the elderly.