Objective:To describe the distribution of fat-free mass (FFM) and fat-free mass index (FFMI) in children aged 3-17 years in China.Methods:Data were collected from National Nutrition and Health Systematic Survey in 0-18 years old children in China. By using multi-stage stratified randomized cluster sampling method, the project was conducted in 28 survey points in urban and rural areas in 14 provinces (autonomous regions and municipalities) in 7 regions in China from 2019 to 2021. FFM was measured using bioelectrical impedance meter. Finally, the body composition data of 70 853 children were included in the analysis. M ( Q1, Q3) was used to describe the gender and age specific FFM and FFMI of the children in different regions. Kruskal-Wallis H rank sum test was used to compare FFM and FFMI of boys and girls in same age group, boys in different age groups, girls in different age groups, as well as boys in same age group and girls in same age group in different regions. DSCF method was used for pairwise comparisons. Results:After the age of 11 years, the difference of FFMI between boys and girls increased year by year. The FFMI was 14.2 kg/m 2 in boys and 13.8 kg/m 2 in girls at 11 years old, the difference was significant ( χ2=135.86, P<0.001). The difference of FFMI between boys and girls exceed 1.0 kg/m 2 from 12 years old, and FFMI was 15.3 kg/m 2 in boys and 14.2 kg/m 2 in girls at 12 year old, the difference was significant ( χ2=597.27, P<0.001). The FFMI was 17.5 kg/m 2 in boys and 14.7 kg/m 2 in girls at 16 years old, the difference was significant ( χ2=2 543.60, P<0.001). The FFMI was higher in boys in northeast China, while the FFMI was lower in both boys and girls in northwest China. Conclusions:Gender specific difference was observed in the increase of FFMI with age. The FFMI was significantly higher in boys than in girls after 11 years old. It is necessary to pay attention to the problem of FFM in children in northeastern and northwestern China.

Objective:To investigate the distribution characteristics of body height, body weight and body mass index (BMI) in children aged 3-17 years in China.Methods:Data were obtained from the National Nutrition and Health Systematic Survey in 0-18 years old children in China. The study selected 70 853 children aged 3-17 years from 28 urban and rural survey sites in 14 provinces (autonomous regions and municipalities) in 7 regions of China with multi-stage stratified cluster random sampling. M ( Q1, Q3) was used to describe the region, age and gender specific body height, body weight and BMI in the children aged 3-17 years. Wilcoxon rank sum test was used to compare the body height, body weight, and BMI between boys and girls in same age group. Kruskal-Wallis H rank sum test was used to compare the body height, body weight and BMI among boys in different age groups and among girls in different age groups, as well as among boys in same age group and among girls in same age group from different regions, and DSCF method was used for further pairwise comparisons. Results:In this study, the median body height and body weight were 172.0 cm and 62.9 kg in 17-year-old boys and 160.0 cm and 53.7 kg in 17-year-old girls. The median for children's body height, body weight, and BMI in most age groups were higher in northeastern and northern China than in southern China, and the differences could be observed until age 17 years. The differences in body weight and BMI in children in northeastern and northern China were greater in Q3 than in Q1 compared with southern China. Conclusions:The body height of children aged 3-17 years continues to increase in China. Northeastern and northern China have more children with higher bodyweight, showing an obvious body weight increase trend, to which close attention needs to be paid.

Objective:To describe the distribution of fat mass (FM), fat mass percentage (FMP), and fat mass index (FMI) in children aged 3-17 years in China.Methods:Data of this study were from the National Nutrition and Health Systematic Survey in 0-18 years old children in China. A total of 70 853 children aged 3-17 years old selected from seven regions of China were included in this analysis. Body composition were measured by using bioelectrical impedance meter. The region, gender and age specific FM, FMP and FMI of the subjects were described by using M ( Q1, Q3). Kruskal-Wallis H rank sum test was used for the comparison of intergroup differences. DSCF method was used for pairwise comparisons. Results:The medians of FM, FMP and FMI were 3.0 kg, 18.3% and 2.9 kg/m 2 in boys aged 3 years and 2.9 kg, 19.0% and 2.9 kg/m 2 in girls aged 3 years, respectively. The FM increased with age and the FMP and FMI decreased with age in both boys and girls aged 3-5 years. After 11 years old, the FM, FMP and FMI decreased first and then increased in boys. From 6-17 years old, the FM, FMP and FMI increased gradually in girls. The FM, FMP and FMI were higher in girls than in boys after 12 years old (all P<0.05). The FM, FMP and FMI were relatively higher in children at the age of 6-14 in northeastern and northern China than in other regions. Conclusions:The age specific FM, FMP and FMI had different changing characteristics in boys and girls aged 3-17 years in seven regions of China. The FM, FMP and FMI also differed with region.

Objective:To analyze the relationship between body mass index (BMI) and fat mass percentage (FMP) in children aged 3-17 years in China.Methods:The BMI and FMP data of children aged 3-17 years from the National Nutrition and Health Systematic Survey in 0-18 years old children in China was analyzed. BMI- Z score/BMI and FMP were used to classify the subjects, respectively. Spearman correlation was used to analyze the correlation between BMI and FMP. The consistency between BMI- Z score/BMI and FMP in classifying the subjects was measured using Kappa coefficient. Results:The FMP of malnutrition, normal and overweight/obesity in boys was higher in age group 10-13-year than in other age groups (all P<0.001). The FMP of all nutritional status in girls increased with age (all P<0.05). The BMI of boys in all the FMP levels increased with age (all P<0.05). When the FMP of girls was 25%- or ≥30%, BMI increased with age (all P<0.001). The relationship between BMI and FMP was strong ( r=0.705, P<0.001), with r of 0.618 in boys and 0.884 in girls. The consistency between BMI- Z score/BMI and FMP in classifying the subjects was found to be moderate (Kappa=0.574, P<0.001). Conclusions:There was a strong relationship between BMI and FMP. The consistency between BMI- Z score/BMI and FMP in classifying the subjects was moderate.

Objective:To evaluate the consistency between bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) in the measurement of body composition in children aged 6-17 years in China.Methods:Fat-free mass, fat mass and fat mass percentage were measured by both BIA and DXA in 1 161 children. t-test or Wilcoxon paired test was used to evaluate the different outcome of the two methods. The correlation and consistency between the methods were evaluated by Spearman correlation coefficients ( r) and Bland-Altman analysis. Results:Body compositions measured by BIA was positively correlated with those measured by DXA (fat mass r=0.95, fat-free mass r=0.98, fat mass percentage r=0.86, all P<0.05). Comparing with DXA, BIA underestimate children's fat mass [the mean difference is -3.15 kg, and the SD is 2.35 kg, 95% limits of agreement (LoA): -7.74-1.45 kg] and fat mass percentage (the mean difference is -8.45%, and the SD is 4.63%, 95% LoA: -17.53%-0.64%). Conclusions:Body compositions measured by BIA was highly positively correlated with those measured by DXA. BIA has certain application value in the measurement of body fat mass and fat-free mass of children aged 6-17 years.

Objective:To survey the awareness status and its influencing factors among parents of preschool children.Methods:Data was collected from the National Nutrition and Health Systematic Survey for 0-18 Year Children in China. A total of 2 625 children aged 3-5 years and their parents living in northern and southern regions of China were randomly selected by multi-stage stratified cluster sampling. The physical measurements were performed for the children, including height and weight; and the body mass index (BMI) and age-for-BMI Z-score (BAZ) were calculated. The questionnaire survey was conducted for the parents, including the demographic characteristics of parents and their children, the perception of their child′s nutritional status (overweight/obesity, normal, wasting) etc. According to WHO standards, the nutritional status of the children was classified as wasting, normal and overweight/obesity. The awareness of parents on their children′s nutritional status was classified as underestimated, correct, overestimated and unclear. Parents′ inability to correctly judge children′s nutritional status was defined as cognitive bias, including underestimation bias and overestimation bias. Multivariate logistic regression model was used to analyze the influencing factors of parents′ underestimation or overestimation of children′s nutritional status.Results:Among 2 625 enrolled preschool children, there were 1 312 boys (50.0%) and 1 313 girls (50.0%); and 648 (24.7%), 944 (36.0%) and 1 033 (39.3%) children aged 3, 4 and 5 years, respectively. One parent (mother, farther or others) of each child was selected for survey, and most of them were mothers (1 998(76.1%)). The prevalence rate of overweight/obesity and wasting was 10.3% (270/2 625) and 1.4% (38/2 625), respectively; and 2 317 children (88.3%) were normal. Among all parents surveyed, 1 766 (67.3%) were correct about their children′s nutritional status (correct group), 612 (23.3%) underestimated their children′s nutritional status (underestimated group), 213 (8.1%) overestimated their children′s nutritional status (overestimated group) and 34 (1.3%) were not aware of their children′s nutritional status (unclear group). The multivariate logistic regression analysis showed that girls ( OR=0.817, 95% CI: 0.678-0.984), living in rural areas ( OR=0.801, 95% CI: 0.662-0.969), large birth weight of child ( OR=0.639, 95% CI: 0.420-0.970) were protective factors for parents underestimating children′s nutritional status. Living in the northern region ( OR=1.698, 95% CI: 1.260-2.290), large birth weight of children ( OR=1.826, 95% CI: 1.149-2.902), father with overweight/obesity ( OR=1.467, 95% CI: 1.089-1.977) and maternal overweight/obesity ( OR=1.778, 95% CI: 1.308-2.417) were the risk factors for parents to overestimate the nutritional status of children. Conclusions:The survey shows that parents of preschool children have a relatively high cognitive bias on the nutritional status of their children. Parents of girls, living in rural areas or having child with large birth weight are less likely to underestimate the nutritional status of children; parents living in northern regions, having a child with large birth weight, or with overweight/obese are likely to overestimate the nutritional status of children.

Objective:To explore the relationship between vegetarian diets and vitamin B 12 levels in Chinese pregnant women. Methods:A cross-sectional survey was used to explore the relationship between vegetarian diets and vitamin B 12 levels in Chinese pregnant women based on data from the Chinese National Nutrition and Health Surveillance (2015-2017). Maternal serum vitamin B 12 concentration was determined by electrochemiluminescence. Background and diet information of all subjects were collected using general and food frequency questionnaires. General Linear Model was used to analyze the difference in serum vitamin B 12 levels between vegetarian and non-vegetarian pregnant women and multivariate logistic regression for examining the relationship between vegetarian diets and vitamin B 12 deficiency (vitamin B 12<150 pmol/L) in pregnant women. Results:A total of 8 366 pregnant women were included in the analysis, and vegetarians accounted for 1.2% (102/8 366). The median serum vitamin B 12 concentrations were 155.8(93.6-212.4) pmol/L and 187.2(127.4-267.6) pmol/L ( Z=－4.22, P<0.001), and the vitamin B 12 deficiency rates were 48.0% (49/102) and 35.0% (2 896/8 264) in vegetarian and non-vegetarian women, respectively. The vitamin B 12 deficiency rate in vegetarian women was 0.89-fold higher than in non-vegetarians (95% CI: 1.24-2.89). Among the vegetarian and non-vegetarian pregnant women, vitamin B 12 deficiency rates during the first, second, and third trimesters were 34.8%(16/46), 54.3%(19/35), 66.7%(14/21), and 20.4%(521/2 559), 32.6%(941/2 886), 50.9%(1 430/2 807), noting for an increasing trend ( Z=23.54 and 2.57, P=0.010 and P<0.001). Conclusions:Vegetarian pregnant women are at high risk of vitamin B 12 deficiency. Compared with non-vegetarian women, vegetarian pregnant women in China have lower vitamin B 12 levels and a higher risk of vitamin B 12 deficiency. Moreover, the risk of vitamin B 12 deficiency will gradually increase during pregnancy.

Objective:To analyze effects of parity on women′s nutrition and health status.Methods:This study was based on the data bank of "Chinese Nutrition and Health Surveillance of Children and Adolescents Aged 0-17 years old and Lactating Mothers from 2016 to 2017". Using a multi-stage stratified random sampling method, 17 771 women at 0 to 24 months postpartum from 31 provinces in Mainland China were included in this study. Questionnaires were used to collect data on women′s general demographic characteristics, parity, mode of delivery, pre-pregnancy weight, pre-delivery weight, diseases before and during pregnancy, postpartum hemorrhage. Current body height, body weight, waist circumference, and blood pressure were measured. Blood hemoglobin, blood glucose and blood lipids were detected. Pre-pregnancy BMI, gestational weight gain, postpartum weight retention, postpartum BMI, the rates of anemia, hypertension, diabetes, and dyslipidemia were calculated. Survey sample weights were calculated according to the sampling design and number of children under 2 years old from the sixth population census data of China. Effects of parity on the observational indicators after adjusting for confounding factors were analyzed by multivariate linear regression and multivariate logistic regression.Results:The age of 17 771 women was (29.5±5.0) years old, 12.2% (2 172) were over 35 but less than 40 years old, and 3.2% (563) were over 40 years old; the women with one parity, two parities, and three parities accounted for 47.3% (8 413), 48.5% (8 620) and 4.2% (738), respectively; urban women accounted for 49.9% (8 875), and rural women accounted for 50.1% (8 896). The results from multivariate linear regression showed that the pre-pregnancy BMI of women with two and three parities was 0.55 kg/m 2 and 0.76 kg/m 2 higher than women with one parity, respectively; the results of multivariate logistic regression showed that the OR(95% CI) of pre-pregnancy anemia was 1.45(1.04-2.02) for women with three parities compared with women with one parity, and the OR(95% CI) of anemia during pregnancy for women with two parities was 1.20(1.06-1.35) compared with women with one parity. Conclusion:Parity is associated with pre-pregnancy BMI and risk of anemia before and during pregnancy in women of reproductive age.

Objective:To analyze effects of parity on women′s nutrition and health status.Methods:This study was based on the data bank of "Chinese Nutrition and Health Surveillance of Children and Adolescents Aged 0-17 years old and Lactating Mothers from 2016 to 2017". Using a multi-stage stratified random sampling method, 17 771 women at 0 to 24 months postpartum from 31 provinces in Mainland China were included in this study. Questionnaires were used to collect data on women′s general demographic characteristics, parity, mode of delivery, pre-pregnancy weight, pre-delivery weight, diseases before and during pregnancy, postpartum hemorrhage. Current body height, body weight, waist circumference, and blood pressure were measured. Blood hemoglobin, blood glucose and blood lipids were detected. Pre-pregnancy BMI, gestational weight gain, postpartum weight retention, postpartum BMI, the rates of anemia, hypertension, diabetes, and dyslipidemia were calculated. Survey sample weights were calculated according to the sampling design and number of children under 2 years old from the sixth population census data of China. Effects of parity on the observational indicators after adjusting for confounding factors were analyzed by multivariate linear regression and multivariate logistic regression.Results:The age of 17 771 women was (29.5±5.0) years old, 12.2% (2 172) were over 35 but less than 40 years old, and 3.2% (563) were over 40 years old; the women with one parity, two parities, and three parities accounted for 47.3% (8 413), 48.5% (8 620) and 4.2% (738), respectively; urban women accounted for 49.9% (8 875), and rural women accounted for 50.1% (8 896). The results from multivariate linear regression showed that the pre-pregnancy BMI of women with two and three parities was 0.55 kg/m 2 and 0.76 kg/m 2 higher than women with one parity, respectively; the results of multivariate logistic regression showed that the OR(95% CI) of pre-pregnancy anemia was 1.45(1.04-2.02) for women with three parities compared with women with one parity, and the OR(95% CI) of anemia during pregnancy for women with two parities was 1.20(1.06-1.35) compared with women with one parity. Conclusion:Parity is associated with pre-pregnancy BMI and risk of anemia before and during pregnancy in women of reproductive age.

Objective:To explore the effects of multifunctional indwelling needle application on the fixation of indwelling peripheral venous needle in children.Methods:Totally 216 children receiving transfusion in the transfusion room of a Class Ⅲ Grade A hospital from June 2018 to March 2019 were selected and divided into the control group ( n=107) and the experimental group ( n=109) according to the random number table. The indwelling needle of children in the experimental group were fixed with the indwelling needle application, while the indwelling needle of children in the control group were fixed with the transparent sticker provided together with the needle. The indwelling time of the indwelling needle, prolapse or displacement of the indwelling needle, curling application, skin damage and residual adhesive tape in the two groups of patients were observed, and the compliance with intravenous infusion and family satisfaction were compared between the two groups. Results:The indwelling time of the indwelling needle of the children in the experimental group was longer than that of the control group; the incidence of indwelling needle prolapse or displacement, curling application, skin damage and residual adhesive tape of the experimental group were lower than that of the control group; the compliance and family satisfaction scores of the experimental group was higher than that of the control group, and the differences were statistically significant ( P<0.05) . Conclusions:The multifunctional indwelling needle application is strongly firm, which can reduce skin damage, prolong the indwelling time of the indwelling needle, and improve the compliance of the children and the satisfaction of family members. It is recommended in the clinical care of children.