Objective: To understand and analyze the current situation and secular trends for prevalence of malnutrition among Chinese children and adolescents aged 7-18 years from 2005 to 2014, and to provide important scientific basis for students' nutrition improvement.Methods: All the subjects aged 7-18 years in both sexes were sampled from 2005, 2010 and 2014 Chinese National Surveys on Students Constitution and Health.According to the new students' health standard of Screening Standard for Malnutrition of school-age children and adolescents(WS/T456-2014) in 2014 of China, the nutritional status of children in 31 provinces (autonomous regions and municipalities, excluding Hong Kong, Macao and Taiwan province) were analyzed and compared in different ages, genders, regions and provinces from 2005 to 2014.The Tibetan students was used with the data of Tibetan minority and all the other students from 30 provinces (autonomous regions, municipalities) were Han minority.Results: The prevalence of malnutrition of children and adolescents of Han minority aged 7-18 years in 2014 was 10.0%.The prevalence of malnutrition components, including stunting, mild wasting and moderate severe wasting, were 0.8%, 3.7%, and 5.5%.Compared with 2005 and 2010, the prevalence of malnutrition of Han children and adolescents in 2014 had declined with 5.0 and 2.6 percentage points, respectively, and its components had declined with 1.0, 1.8, 2.2 and 0.4, 1.1, 1.2 percentage points, respectively.The prevalence of malnutrition of 2014 in boys was higher than in girls (11.1% vs.8.9%), the rural was higher than the urban (11.0% vs.9.1%) and the west (11.7%) was higher than the east (9.0%) and the middle (9.2%).Mild wasting of Chinese children and adolescents aged 7-18 years was the main component in malnutrition and the stunting in the Han and Tibetan children and adolescents only accounted for 8.0% and 7.5%, respectively.Compared with 2005 and 2010, the prevalence of malnutrition for Chinese children and adolescents aged 7-18 years in 2014 had declined with various extents constantly, and there was a statistically significant difference among three surveys (P<0.05).Provinces (autonomous regions, municipalities) with high prevalence of malnutrition mainly concentrated in the southwest of China from 2005 to 2014.Compared with 2005 and 2010, the prevalence of malnutrition declined in 31 provinces (autonomous regions, municipalities) of China in 2014.The number of provinces (autonomous regions, municipalities) with high prevalence of malnutrition decreased constantly and increased for the number of province (autonomous regions, municipalities) with low prevalence.Conclusion: The prevalence of malnutrition among Chinese children and adolescents aged 7-18 years had declined from 2005 to 2014, but the total prevalence of malnutrition was still high.Mild wasting was the main component in malnutrition and the prevalence of stunting was low.Provinces (autonomous regions, municipalities) with high prevalence of malnutrition mainly concentrated in the southwest of China.

Objective: To understand the status of vision of Tibetan students aged 7-18 in China, and to provide the theoretical basis for prevention and controlling work of short-sightedness and making relevant policies. Methods: Cross-sectional survey method was applied to collect information of the eyesight of 2 418 Tibetan students and that of gender, age and work-and-rest habit of 1 910 students, and the status of eyesight of Tibetan students was analyzed, and Logistic regression analysis method was used to probe into the influencing factors of eyesight. Results: The mean left eye visual value was (4.75±0.33),and the median was 4.75(P25=4.5，P75=5.0). The mean right eye visual value was (4.74±0.33),and the median was 4.90(P25=4.5, P75=5.0). 1 520 students were detected with myopia, with the detection rate of 62.9%. The prevalence of myopia among Tibetan female students was higher than that of male (P<0.01). The detection rate of myopia was increased with age both in left and right eyes. Logistic regression model showed that students with insufficient physical education courses each week were associated with evaluated risk of myopia,compared with those with sufficient courses(OR=1.43, 95%CI=1.05-1.94, P<0.05). Conclusion The prevalence of myopia among Tibetan students aged 7-18 years old is rather high, and females are worse than males, senior students were worse than junior students. After controlling for factors like grade and gender, insufficient physical education courses at school is a risk factor of myopia.

Objective: To investigate the prevalence of drinking-tea type endemic fluorosis among children in Lhasa, Tibet, and to provide basic data for the early prevention of dental fluorosis and skeletal fluorosis among children. Methods: Stratified cluster random sampling method was used to select primary school 1 991 students in 6 counties. Results: The detection rate of dental fluorosis was 27.2%, the index of dental fluorosis was 0.44, and the total severity of fluorosis prevalence was identified as very mild among 6 counties. The detection rate of dental fluorosis increased with the age of the children：male and female increased by 36.2 and 28.5 percentage points,respectively. There was no significant difference between male and female students(χ2=0.08, P> 0.05). The urine fluoride test results suggested that urine fluoride concentration among participate children was below the standard limits value(geometric mean of urinary fluorine <1.4 mg/L). Conclusion The prevalence of tea-drinking type endemic fluorosis among children in Lhasa is more serious compared with that from other regions of China. The cumulative effect of fluorine in human body makes older students more prone to dental fluorosis. It is suggested that more school-based health education programs should be carried out to prevent tea drinking type endemic fluorosis.

Objective: To investigate the prevalence of metabolic syndrome (MS) among children and adolescents aged 10-16 years old in 7 provinces in China. Methods: Using the method of stratified cluster random sampling, 93 primary and secondary schools were selected from Guangdong, Hunan, Liaoning, Shanghai, Chongqing, Tianjin, and Ningxia provinces in China. A total of 9 296 students aged 10-16 years old with complete physical and biochemical parameters were selected as the subjects of the present study from above 93 primary and secondary schools. MS was determined using the definition of 'guideline of 2010 Chinese children and adolescents MS definition and treatment’. The standardized age-sex composition of the 2010 census was used to standardize the MS detection rate of every province. Chi-square test was used to compare the difference of MS prevalence among participants with different characteristics. Results: The prevalence of MS was 4.1% (384/9 296) among children and adolescents aged 10-16 years old in 7 provinces in China. The prevalence of MS among males was 5.0% (237/4 754), which was significantly higher than females (3.2%) (147/4 542) (P<0.05). Stratified by nutrition conditions, the prevalence of MS was 0, 0.6% (39/6 733), 8.9% (104/1 170), 30.0% (241/803) for thin, normal weight, overweight, and obese population, respectively. The MS prevalence increased with the increase of body mass index (BMI) (P<0.001). Stratified by provinces, the prevalence of MS was the highest in Tianjin (9.2%) and the lowest in Hunan province (0.8%). Conclusion The prevalence of MS was high among children and adolescents aged 10-16 years old in 7 provinces in China. MS prevalence among males was higher than females; MS prevalence among overweight/obese population was higher than normal weight population. The detection rate of metabolic syndrome was different in different provinces.

Objective: To understand the distribution of masculine and feminine traits and gender roles in primary school students who did not enter the Tanner Ⅱ stage in Xiamen and to provide a reference for promoting the development of mental and physical health of children. Methods: The present study was based on the blood pressure cohort of children in Xiamen. All 823 participants were from grade two, three, four of primary school. Participants were asked to obtain children’s masculine and feminine traits, gender role types (masculine, feminine, androgynous, undifferentiated) and heterogeneity through the Children’s Sex Role Inventory. In this study, non-parametric tests and chi-square tests were used to compare the differences of masculine and feminine traits, gender role types and heterogeneity rates between different groups. Results: The masculine traits of this study scored (2.80±0.52), and the feminine traits scored (2.95±0.55). The proportion of masculine, feminine, androgynous and undifferentiated was 12.8%, 11.9%, 39.1% and 36.2%, respectively. The proportion of undifferentiated among boys (41.8%) was higher than girls (31.5%), while the proportion of androgynous (34.6%) was lower than girls (43.0%), the differences were of statistical sigificance(χ2=9.22, 6.02, P<0.05). The rate of gender role heterogeneity was 7.0%, and there was no significant difference between different gender and age groups(P>0.05). Conclusion The gender roles of primary school students in Xiamen are mainly androgynous and undifferentiated, and the distribution of gender role is different in boys and girls. More specifically, the gender roles of boys were mainly undifferentiated, and girls were mainly androgynous. In general, the proportion of gender role heterosexuals is a little higher, which should be paid more attention and appropriate guidance by schools and parents.

Objective: To explore the epidemiological characteristics of injury among middle school students in Zhongshan city, Guangdong Province, and to provide evidence for appropriate student injury prevention strategies and injury monitoring programs. Methods: The cluster random sampling method was used to collect injury information among 2 212 middle school students in urban and suburban areas of Zhongshan city. SPSS 22.0 was used for statistical analysis. Results: Among all the 2 212 middle school students, the incidence of injury was 17.95%. The incidence of injuries (20.9%)and mutiple injuries(6.67%)among boys was higher than that of girls(15.42%,4.61%),and the differences were of statistical significance(χ2=11.21,4.45,P<0.05). The incidence of multiple injuries among junior high school students(6.70%) was higher than that among high school students(4.48%)(χ2=5.20，P<0.05). The injury occurred in the school (63.76%) was higher than that occurred outside of the school (36.24%). Most injures were more likely to occur in sports area in school(33.16%),and most injuries were found occured while doing physical activities(38.01%). Conclusion The prevention of injury among middle school students should focus on junior high school students and male students. School-based injury prevention and health education should focus on campus sports-related injury.

Objective To analyze the level of hemoglobin level and the prevalence of anemia in students aged 7-14 years in China.Methods According to the 2010 Chinese National Surveys on Students' Constitution and Health,71 130 students who were aged 7,9,12 and 14 years and had received hemoglobin test were sampled as the subjects,WHO anemia diagnostic criteria was used to explore the hemoglobin level and the prevalence of anemia.Results The mean concentrations of hemoglobin were (129.25 ± 11.37) g/L,(131.04 ± 11.08) g/L,(135.02 ± 12.12) g/L and (138.47 ± 13.97) g/L and the prevalence of anemia was 9.0％,6.5％,8.6％ and 7.7％ respectively in 7,9,12 and 14 years old students.The prevalence of anemia was 9.7％ in girls,significant higher than that in boys (6.2％),and 8.8％ in rural students,significantly higher than that in urban students (7.1％).The hemoglobin levels were (133.19 ± 12.56) g/L,(133.28 ± 12.76) g/L,(134.24 ± 12.73) g/L and (133.79 ± 12.16) g/L and the prevalence of anemia were 8.8％,8.3％,6.7％ and 5.9％ respectively in thin,normal,overweight and fat students,there were significant differences among four groups.Conclusion The prevalence of anemia in students aged 7-14 years in China was still high,and there was significant differences among different gender,area,age and nutritional status groups.

Objective: To analyze the association between masculine and feminine traits, gender role in students and family factors, and to provide a scientific basis for promoting the healthy development of children and adolescents gender role. Methods: Cluster random sampling method was used to selected 823 students from 2 schools of Xiamen in May, 2018, participants were asked to report individual masculine and feminine traits through the Child s Sex Role Inventory, and then gender role was divided into four types (masculine, feminine, androgynous, undifferentiated). Non parametric tests, generalized linear model, and Logistic regression model were used to explore the association between masculine and feminine traits, gender role and family factors. Results: Compared with the boys from the nuclear family, the masculine traits were lower in boys of other families by 0.282( 95% CI = -0.452 --0.110), and the feminine traits were also lower by 0.192 (95% CI =-0.369--0.014). Compared with boys of middle socioeconomic status (SES), the masculine traits of boys from low SES decreased by 0.157 (95% CI =-0.286--0.029), and the feminine traits decreased by 0.140 (95% CI =-0.274--0.005). The proportion of androgynous in boys from other families was significantly lower than boys from the nuclear family ( OR =0.45, 95% CI =0.21-0.94), with the proportion of undifferentiated significantly higher than nuclear family 2.33 (95% CI =1.22-4.44). The proportion of androgynous in boys from low SES was significantly lower than boys from middle SES ( OR =0.59, 95% CI =0.35-0.99), with the proportion of undifferentiated significantly higher than middle SES 1.62 (95% CI =1.00-2.65). Among girls, the differences in masculine and feminine traits and gender role of different family factors were not statistically significant ( P >0.05). Conclusion The masculine and feminine traits and gender role in students are associated with family structures and socioeconomic status, especially in boys. Therefore, the family environment is an important factor affecting children s gender role, and the healthy development of children s gender role needs parents attention and correct guidance.

Objective: To analyze the correlation between the scores of masculinity and femininity and parental rearing pattern in lower grade primary school students in Xiamen, and to provide a policy suggestions and reference basis for establishing a correct concept of gender role among children and adolescents. Methods: A cluster random sampling method was used to select 823 students from two primary schools in Xiamen. Masculinity and femininity scores were assessed by Children s Sex Role Inventory(CSRI), while attitudes and behaviors of parental rearing pattern were obtained through EMBU. Regression analyses were used to analyze the correlation between masculinity and femininity scores and parental rearing pattern. Results: Masculinity scored 2.82 ( 2.41 ,3.24) and 2.82 (2.47,3.18), femininity scored 2.87 (2.40,3.20) and 3.13 (2.73,3.47) among boys and girls, with no significant gender difference ( P >0.05). Masculinity and femininity scores varied significantly by parental emotional warmth and understanding(father: Z/H =44.61, 37.24；mother: Z/H=41.68, 46.64, P <0.05). Among boys, increasing parental emotional warmth and understanding and paternal excessive interference were associated with higher masculinity and femininity scores. Increasing rejection and maternal deny were associated with lower masculinity scores. Among girls, increasing the understanding of emotional warmth of fathers was associated with masculinity and femininity scores, increasing excessive interference from mothers was associated with lower masculinity scores ( P <0.05). Conclusion There are gender differences in the relationship between parental rearing pattern and masculinity and femininity scores. In particular, increasing parents emotional warmth and understanding and reducing mothers punishment and harshness, rejection and denial, and other negative parenting styles could facilitate healthy development of masculinity and femininity among primary school students.

Objective: To explore the association between breastfeeding and the type of obesity in children and adolescents, and to provide a theoretical basis for the identification and intervention of influential factors of different types of childhood obesity. Methods: Using stratified cluster sampling method, 93 primary and secondary schools in 7 provinces and cities in China were selected for physical examination and questionnaire surveys. Totally, 30 437 primary and middle school students aged 7-17, with completed information, were selected. A multivariable Logistic regression model was used to analyze the association between breastfeeding and different types of obesity. Results: The breastfeeding rate of students was 69.8%. The rates of general obesity, simple abdominal obesity, and combined obesity in the breastfeeding group were 7.1%, 3.9%, and 18.7%, the non-breastfeeding group were 7.0%, 4.7%, and 19.5%. The differences were statistically significant(χ2=14.04,P<0.01). Univariate analysis found that breastfeeding significantly reduced the risk of simple abdominal obesity in children and adolescents(OR=0.81,95%CI=0.72-0.92,P<0.01) with normal(BMI non-overweight and obesity and waist Conclusion Breastfeeding is a protective factor for children with simple abdominal obesity and combined obesity, and the rate of breastfeeding in China should be further improved.