[Secular changes of physical growth in students of Zang-tribe in Tibet during 1965-2004].

OBJECTIVE: To analyze the secular changes of physical growth in 7-17 year old students of Zang-tribe in Tibet during 1965-2004, and to make suggestions for further improvement. METHODS: The data collected by local government in 1965 and Chinese national survey on students' physical fitness and health in 1985, 1995 and 2004 were used to analyze and find out the differences from the students' stature, body weight, chest girth, and BMI in different years, and to compare the increasing rate per 10 years in different periods of time. RESULTS: Levels on stature, body weight and chest girth were increased significantly among 7-17 year-old students of Zang-tribe in Tibet during 1965-2004. From 1965 to 1985, the levels of stature and body weight were increased 11.4 cm and 5.0 kg respectively among male Zang-tribe students, 9.1 cm and 3.9 kg among the female. During 1985-2004, stature levels of Zang-tribe students was kept rising in much less extent, while average levels of body weight were reaching up remarkably, especially in 1995-2004, in which the average increasing rate per 10 years had achieved 14.8% and 13.4% among the male and female students aged 7-17 years old respectively. Levels of chest girth were increased rapidly in 1965-1985, showing a higher increasing rate in male students (2.7%) than in female students (1.9%). In 1985-2004, the increasing rates fell obviously both in male and female students, but there existed a higher rate in 1995-2004 than in 1995-1985, especially for females (4.0%). Upon the secular changes of stature and body weight, the levels of BMI were decreased in 1985 as comparing to those in 1965, then increased rapidly in 1985-2004, especially in 1995-2004, having an increasing rate up to 12.6% and 12.4% respectively in male and female students. CONCLUSION: Secular changes on physical growth among 7-17 year-old students of Zang-tribe in Tibet were paralleled with the economic progress in 1965-2004, giving active effects by economic progress and nutrition improvements to the physical growth of children and adolescents.