Research on the Trend of the Height of Han Students Aged 7-18 in China

Aims To make time series analysis on the 29-year (1985−2014) trends in height among Han Students Aged 7-18 in China and predict their future height from the perspective of interdisciplinary studies of demography and physical education. Methods The data were from the findings of seven cross-sectional surveys from the Chinese National Survey on Students’ Constitution and Health (CNSSCH). The mean, standard error, variance analysis, trend test, F test, T test, development growth and growth rate were used to make a descriptive analysis of height trends. The ARIMA model in the time series analysis was applied to predict the height development of Han students in 2024. Results The height of students aged 7-18 substantially increased from 1985 to2014. The mean of the height of boys increased by 3.99 cm, 8.01 cm, 8.31 cm, 8.63 cm, 9.81 cm, 11.62 cm, 10.38 cm, 9.22 cm, 7.50 cm, 5.59 cm, 4.51 cm, and 3.79 cm, respectively. The mean of the height of girls increased by 6.66 cm, 7.36 cm, 8.00 cm, 8.84 cm, 9.60 cm, 8.66 cm, 5.57 cm, 4.65 cm, 3.95 cm, 3.32 cm, 2.87 cm and 3.32 cm, respectively. The increasing disparity of the sex differential in the mean height was also observed. From 1985 to 2014, the mean of height difference between boys and girls aged 7-18 had been increased constantly. Their mean height differences were 3.27 cm, 4.03 cm, 4.64 cm, and 5.13 cm, respectively in 1985, 1995, 2005, and 2014. A narrowing of the urban−rural differential in the mean height was observed. In 1985, on average, urban boys aged 7-18 were 4.18cm higher than rural boys in the same age group. And the height differences between urban and rural boys in the same age group were 3.58 cm, 3.18 cm and 2.41 cm, respectively in 1995, 2005 and 2014. According to comparison results, the mean height of urban girls was greater than that of rural girls, and the height difference between urban and rural girls had been constantly narrowed as well. The results of 4 comparisons showed that the height differences between urban and rural girls were 3.68 cm, 3.12 cm, 2.62 cm, and 1.98 cm, respectively. Conclusions There was a general increase in the height of Chinese Han students aged 7-18 in the past 29 years and difference between sex, rural-urban and age have been observed. In 2024, the height of students will continue to grow.