Objective: To analyze the urban-rural disparity of childhood stunting and its association with subnational economic growth among Chinese Han students aged 7-18 years. Methods: We used the data from 2014 Chinese National Survey on Students′ Constitution and Health. 213 940 Chinese Han students aged 7-18 years with complete height records were included in this study. Stunting was defined according to the Screening Criteria of Malnutrition for School-age Children and Adolescents(2014 version, in Chinese). We divided students into two groups (economically developed and underdeveloped areas) according to the provincial GDP per capita. Spearman correlation coefficient was used to explore the association between the difference of urban-rural stunting prevalence and the provincial GDP per capita. Logistic regression models were established to assess the risk of stunting in rural children compared with urban children. Results: Among 213 940 students, 107 033 (50.0%) were from urban areas. The average height of 7-18 years old and 18 years old [(152.9±15.7) and (166.1±8.7) cm] of urban students were both higher than those of rural students [(150.7±16.0) and (165.1±8.6) cm] (P<0.001). The stunting prevalence of Chinese urban students (0.4%) was statistically significant lower than that of rural students (1.1%) (P<0.001), which was consistent in all age groups (P<0.05). The urban-rural disparity was found in 60% (18/30) of Chinese provinces. The difference of urban-rural stunting prevalence was negatively associated with provincial GDP per capita (r=-0.62, P<0.001). In economically underdeveloped areas, the risk of stunting for rural students aged 7-9 years was 4.69 (95%CI: 2.93-7.52) times that for urban children, while for students aged 10-18 years, the odds ratio was 2.44 (95%CI: 2.02-2.96). In economically developed areas, the risk of stunting for rural students aged 7-9 years was 5.43 (95%CI: 3.67-8.03) times that for urban children, while for students aged 10-18 years, the odds ratio was 2.15 (95%CI: 1.85-2.49). Conclusions The urban-rural disparity of childhood stunting existed in most places in China. The difference of growth retardation between urban and rural areas was related to regional economic development.

Objective: To compare the prevalence of growth retardation in students aged 7-18 years from 26 minority ethnic groups in China and provides reference evidence to promote the growth and improve the health status of students in minority ethnic groups. Methods: The body height data of students aged 7-18 years in 26 minority ethnic groups in 2014 Chinese National Surveys on Students’ Constitution and Health were used for the analysis and comparison. Growth retardation was defined according to the school-aged child and adolescent malnutrition screening standard (WS/T 456-2014). Results: In 2014, the average body heights of school boys and school girls aged 18 years in 26 ethnic minority groups were (168.3±6.8) cm and (156.2±5.9) cm respectively. The overall growth retardation prevalence rate of school boys and school girls in 26 ethnic groups were 5.4% and 5.1%, respectively. The growth retardation prevalence rate was highest in students of Shui ethnic group (24.5% for boys and 23.0% for girls), and lowest in students of Hui ethnic group (0.1% for boys and 0.3% for girls). The growth retardation prevalence rates in 9 ethnic minority groups were higher than the average level, in these 9 ethnic groups, the differences in prevalence rates of boys of Buyi ethnic group, girls of Lisu ethnic group and girls of Hani ethnic group had no significance among four age groups. Growth retardation in students of Sala ethnic group was mainly observed in age group 7-9 years, but in others ethnic group, for example, Wa ethnic, it was mainly observed in older age group. The students in minority ethnic groups in southwestern China had the highest growth retardation prevalence rate (8.1%), significantly higher than that in northern China (0.8%) (OR=10.6, 95%CI: 7.8-14.4). The overall growth retardation prevalence rate between 7 and 17 years old was negatively correlated with the body height of 18 years old (boys: r=-0.811, P<0.001; girls: r=-0.715, P<0.001). Conclusions In 2014, the differences in body height among students aged 18 years in 26 minority ethnic groups in China were significant. In general, the first five minority ethnic groups with high detection rate of growth retardation in boys were Shui, Wa, Buyi, Yao and Yi, and the five minority ethnic groups with high detection rate of growth retardation in girls were Shui, Yao, Buyi, Wa and Miao. The detection rate of growth retardation was highest in students of minority ethnic groups in southwestern China. Nutritional interventions and healthy education should be carried out in minority ethnic groups and areas with high growth retardation prevalence rate to promote the growth of the students.

Objective: To describe the subnational disparity of anemia among Chinese Han students aged 7-14 years, and to provide a reference for making intervention measures to improve anemia among Chinese children. Methods: A total of 71 115 Chinese Han students aged 7-14 years were selected from the project ‘2014 Chinese National Survey on Students’ Constitution and Health'. Anemia and its severity were defined according to the diagnosis criteria of World Health Organization (WHO). The rank sum test was used to compare anemia distribution of different subgroups. Logistic regression models were established to analyze the influencing factors of anemia and moderate-to-severe anemia. Results: In the 71 115 students with measured hemoglobin concentrations in the 2014 CNSSCH, the overall prevalence rate of anemia was 8.9%, with 5.8% to be mild anemia and 3.1% to be moderate-to-severe anemia. For boys aged 7-14 years, the hemoglobin concentration increased with age; Boys aged 7 years had the highest anemia prevalence (9.8%) and moderate-to-severe anemia prevalence(4.4%). For girls aged 7-12 years, the hemoglobin concentration increased with age, but the concentration decreased a little when girls reached 14 years of age; 14-year-old girls had the highest prevalence of anemia(13.3%), and 7-year-old girls had the highest prevalence of moderate-to-severe anemia(4.8%). The highest prevalence rates of anemia were found in Hainan (24.1%) and Gansu(19.6%), while the lowest was in Beijing(2.0%). Logistic regression models revealed that, for children aged 7 and 9 years, when comparing to those lived in urban areas, living in rural areas appeared to be a risk factor for anemia (OR=1.34) and moderate-to-severe anemia(OR=1.48); when comparing to living in cities of upper socio-economic status, living in cities of intermediate socio-economic status appeared to be a risk factor for anemia (OR=1.43) and moderate-to-severe anemia(OR=1.41), and living in cities of lower socio-economic status also appeared to be a risk factor for anemia (OR=1.26) and moderate-to-severe anemia(OR=1.35). For students aged 12 and 14 years, girls were at higher risks for anemia and moderate-to-severe anemic(OR=2.41，2.20). Conclusion The overall prevalence of anemia was low in Chinese school-aged children, but substantial subnational disparity and subgroup disparity exists. Our data called for setting up context-specific measures, such as deworming and iron supplementation, to deal with child anemia. Intervention programs need to be implemented among adolescent girls and those with relatively low socioeconomic status.

Objective: To describe the current situation of spermarche/menarche of 13 ethnic minority groups in China in 2014, and analyze the association between spermarche/menarche and nutritional status among ethnic minority groups. Methods: The sample of 13 ethnic minorities (Bai, Hani, Dai, Lisu, Wa, Naxi, Miao, Shui, Buyi, Dong, Zhuang, Yao and Qiang) from Yunnan, Guizhou, Sichuan province and Guangxi Zhuang autonomous region were selected from Chinese National Survey on Students′ Constitution and Healthy of 2014. A total of 25 964 students with completed records of height, weight, spermarche and menarche were selected, including 11 276 boys aged 11-18 years old and 14 688 girls aged 9-18 years old. Probit analysis was used to calculate the median age at spermarche or menarche. All subjects were classification into four nutritional status groups (normal, malnutrition, overweight and obesity) according to the Screening standard for malnutrition of school-age children and adolescents (WS/T 456-2014) and the Screening for overweight and obesity among school-age children and adolescent (WS/T 586-2018) of China. Binary logistic regression was used to analyze the association between spermarche, menarche and nutritional status. Results: The median age at spermarche (95%CI) of 13 ethnic minorities were ranged from 13.4 (13.1, 13.7) years old to 15.3 (15.1, 15.5) years old. In the 11 -year age group, all ethnic girls experienced menarche. The median age at menarche (95%CI) of 13 ethnic minorities were ranged from 12.1 (11.4, 12.7) years old to13.6 (13.4, 13.7) years old. Logistics regression analysis showed that students with malnutrition experienced spermarche or menarche later than normal weight students, the OR (95%CI) for boys about 0.49 (0.42, 0.56) and girls about 0.15 (0.12, 0.19), while overweight and obese students entered puberty at earlier age, the OR (95%CI) for boys about 1.37(1.10, 1.72) and girls about 3.21(2.51, 4.12). Conclusion Boys from 13 ethnic minorities began to have spermatorrhea at the age of 13, and girls from 13 ethnic minorities began menstruating at the age of 9 in 2014. Nutrition status was closely related to spermarche and menarche.

Objective: To examine the relation between physical fitness and frequency of having breakfast among Chinese Han college students so as to provide proper intervention and theoretical basis for improving college students’ physical fitness. Methods: The data from 2014 Chinese National Survey on Students’ Constitution and Health (CNSSCH) was used. The data of 47 172 Han students were calculated, the chi-square test wasused to compare the differences of the physical fitness passing rate in different subgroups of college students. The Log-binomial model was established to assess the relation between physical fitness and breakfast consumption. Results: The unqualified rate of physical fitness was 22.8%. Boys(24.7%), urban students (25.7%), and those who exercised less than one hour per day (23.3%) had lower physical fitness passing rates than girls(20.9%), rural students (19.9%) and those who exercised more than one hour per day (20.3%)respectively(χ2=101.38, 223.33, 32.20,P<0.01). The unqualified rate of physical fitness increased by age. The unqualified rate of physical fitness in eastern, central and western regions was 21.2%, 21.7% and 25.1% respectively. The unqualified rate of physical fitness for those with normal nutritional status (18.2%) was significantly lower than those who were underweight (26.0%) or overweight/obese(42.6%)(χ2=1 660.50, P<0.01). In this study, 53.2% of college students had breakfast every day,unqualified rate of physical fitness was higher among students with less regular consumption of breakfast(χ2=393.50, P<0.01). The Log-binomial model showed that the college students who had 3-5 breakfasts(PR=1.16, 95%CI=1.11-1.20), 1-2 breakfasts(PR=1.34, 95%CI=1.28-1.40), never had breakfast (PR=1.43, 95%CI=1.32-1.53) per week had higher physical fitness failure rates than those who had breakfast every day. Conclusion There is a significant association between physical fitness and breakfast consumption among college students. Developing the good habit of having breakfast is not only the component of healthy lifestyle but also an indispensable part to the improvement of college students’ physical fitness.