中文摘要：

目的调查重庆市儿童青少年青春发动时相与肥胖及体成分的关系,比较男女生青春期体格和体脂发育的差异。方法采用目的抽样的方法,选取重庆市九龙坡区两所九年一贯制学校的1447名7-17岁中小学生进行身高、体重、腰围和皮褶厚度的体格检查,同时进行女生乳房发育、初潮年龄和男生睾丸容积、阴毛发育的调查。结果女生乳房发育Ⅱ期平均年龄为9.78岁,初潮平均年龄12.32岁。男生睾丸发育Ⅱ期平均年龄为11.50岁,阴毛发育Ⅱ期平均年龄为12.62岁。女生青春期发动提前组超重率（18.8%）大于非提前组（7.7%）,差异有统计学意义（χ-2=8.881,P=0.005）;提前组肥胖率（18.7%）高于非提前组（1.5%）,差异有统计学意义（χ-2=40.653,P〈0.001）,且青春发动时相提前与体重存在秩相关（r=0.324,P〈0.001）;男生青春发动时相提前组超重率（17.9%）高于非提前组（8.3%）,差异有统计学意义（χ-2=5.134,P=0.047）,且青春发动时相提前与体重存在秩相关（r=0.103,P=0.030）。女生所有体成分指标均为青春发动时相提前组〉适时组〉延迟组,差异均有统计学意义（P〈0.001）;男生青春发动时相提前组的瘦体重（46.718±1.186）〉适时组（42.114±0.437）〉延迟组（37.899±0.944）,差异有统计学意义（F=14.870,P〈0.001）。结论重庆市女生超重、肥胖及体成分与青春发动时相提前相关联,男生超重及瘦体重与青春发动时相提前相关联。

英文摘要：

Objective To investigate the correlation of pubertal timing,obesity,and body composition in children and adolescents in Chongqing city, China, and the difference in physical development and body fat among male and female students during puberty. Methods By a purposive sampling method,1447 primary and junior high school students（ 7- 17 years old） from two 9- year coherent-style schools in the Jiulongpo district（ Chongqing City） were selected as research subjects. Height,weight,waist circumference,and skinfold thickness of the subjects were measured. In addition,breastdevelopment and age at first menstruation among female students and testicular volume and pubic hair development among male students were investigated. Results The average age at stage Ⅱ breast development for female students was 9. 78 years,while the average age at first menstruation was 12. 32 years. The average age at stage Ⅱ testicular development for male students was 11. 50 years,while the average age at stage Ⅱ pubic hair development was 12. 62 years. The incidence of overweight in female students from the group with early pubertal timing（ 18. 8%） was found to be significantly higher than that of students from the group with normal pubertal timing（ 7. 7%）（ χ-2= 8. 881,P = 0. 005）,while the incidence of obesity in the group with early pubertal timing（ 18. 7%） was found to be significantly higher than that of the group with normal pubertal timing（ 1. 5%）（ χ-2=40. 653,P〈0. 001）. Spearman rank correlation analysis showed that early pubertal timing in female students was positively correlated with their weight（ r = 0. 324,P〈0. 001）. The incidence of overweight in male students from the group with early pubertal timing（ 17. 9%） was found to be significantly higher than that of the group with normal pubertal timing（ 8. 3%）（ χ-2= 5. 134,P = 0. 047）. Spearman rank correlation analysis also showed a positive correlation between early pubertal timing in male students and their weight（ r =0. 10