Objective: To understand the hydration status and related factors of rural boarding primary school students, so as to provide a scientific basis for drinking water health intervention for primary school students. Methods: In November 2023, a convenience sampling approach was employed to conduct a hydration status survey among 144 boarding students in grades 5 and 6 of a rural primary school in Guangxi. The Duplicate meal method and weighing method were utilized to measure the food derived water intake over three consecutive days. Urine osmolarity of students was measured on site for three days, and a simple physical examination was also carried out. A self administered questionnaire was used to investigate students drinking water literacy, daily water intake, and physical activity levels. Meanwhile, a drinking water literacy survey was conducted among 21 substitute teachers and 144 parents of the boarding students in grades 5 and 6. Logistic regression was used to identify factors associated with students hydration status. Results: The median daily total water intake of students was 2 043.55 mL, and 54.86% of the students did not reach the recommended Adequate Intake (AI). The median food derived water intake was 1 149.24 mL, accounting for 53.94% of the total water intake. Univariate analysis revealed that the daily drinking frequency, daily water intake, and food derived water intake of students were related factors of hydration status ( β =-1.60, -1.01, -0.00, all P <0.05). Multivariate Logistic regression analysis showed that primary school students with a daily drinking frequency of ≥7 times were more likely to maintain an adequate hydration status ( OR =0.28, 95% CI =0.09-0.93, P ＜0.05). Conclusions The water intake from food is the main source of water in the body for boarding primary school students in a certain rural school in Guangxi. Primary school students should increase their water intake frequency appropriately to maintain an adequate hydration status.

Hepatitis B is a major global public health issue. Through the implementation of comprehensive prevention and control strategies centered on hepatitis B vaccination， China has achieved remarkable progress in hepatitis B prevention and control， while there are still many issues and challenges. This article reviews the development of hepatitis B vaccination strategies in China， analyzes the goal and advances in vaccination in different populations， and problems and challenges， in order to provide a reference for further optimizing vaccination strategies and improving the levels of prevention and control.

In 2016， the World Health Organization proposed the vision of eliminating viral hepatitis as a public health threat by 2030， and since then， China has actively promoted the elimination of hepatitis C as a public health threat and has made great achievements by formulating policies， clarifying main tasks， focusing on key issues， and implementing prevention and treatment measures. This article reviews the advances and achievements in China’s actions to eliminate hepatitis C as a public health threat since 2016， analyzes the existing problems and challenges， and puts forward recommendations for future prevention and control strategies， in order to provide a reference for achieving the goal of eliminating viral hepatitis as a public health threat by 2030.

Over the past three decades， China has made significant progress in the prevention and control of viral hepatitis， and the incidence rates of new-onset pediatric hepatitis B virus infections and acute viral hepatitis in the population have reduced to a relatively low level； however， there is still a heavy disease burden of chronic viral hepatitis in China， which severely affects the health status of the population. This study systematically summarizes the achievements of viral hepatitis prevention and control in China， analyzes existing problems and challenges， and proposes comprehensive prevention and control strategies and measures to eliminate viral hepatitis as a public health threat based on the national conditions of China， in order to provide a reference for related departments in China on how to achieve the action targets for eliminating viral hepatitis as a public health threat by 2030.

Objective: To explore the relative importance of different food attributes and levels in food decision making of school aged children, and to understand their meal preferences, so as to provide the evidence for formulating precise intervention strategies for dietary behaviours of school aged children. Methods: From May to June 2024, a total of 854 children aged 11 to 15 years old were selected from 2 middle schools (each school in urban and rural areas) in both Hubei Province and Anhui Province by stratified cluster random sampling method to conduct a D-optimal discrete choice experiment. The mixed Logit model was used to analyze children s preference for meal attributes and different levels, and to calculate the relative importance (RI) of attributes and willingness to pay (WTP) in meal choices. Results: The included five food attributes had statistical significance on meal choice of school aged children ( P <0.05). The relative importance of food attributes affecting the meal choices of school aged children in descending order were dining mode ( RI =31.26%), food varieties ( RI =30.56%), cooking method( RI =23.84%), taste( RI =8.06%) and price ( RI =6.27%). Among them, school aged children preferred home cooked meals ( β =0.74) (WTP=86.3 yuan),varied foods(grain/tubers+vegetables+fish, meat, eggs and beans) ( β =0.61) (WTP=71.9 yuan), fried/roasted cooking ( β =0.51) and spicy taste ( β =0.33).Price was negatively correlated with meal choices( β =-0.01) ( P <0.05). Based on residential area and body mass index (BMI), the stratified analysis showed that dining mode was highest in the relative importance for rural children with overweight and obese children ( RI =31.28%,34.17%), both of whom preferred home cooked meals ( β =0.76, 0.91), and meals containing fish, meat, eggs and beans with grain/tubers or grain/tubers and vegetables in terms of food choice (area: β =0.53, 0.53 ; BMI: β =0.55, 0.56) ( P <0.05). Conclusions School aged children have different preferences for different attributes of meals. The quality of school meals should be improved,the cost of buying healthy meals should be reduced,targeted family health education should be carried out,and healthy cooking methods should be advocated.

Background The decline of physical activity in the elderly due to aging may increase the risk of sarcopenia. Currently, there is a lack of evidence from large natural populations on the relationship between PA and sarcopenia. Objective To explore the relationship between PA and sarcopenia in the elderly aged 60 years and above in 10 provinces (autonomous regions) of China. Methods Data were retrieved from the 2022—2023 round of the China Development and Nutrition Health Impact Cohort. Personal basic information and PA data were collected by questionnaire survey. Skeletal muscle mass was measured by bio-electrical impedance analysis, muscle strength was measured using a grip dynamometer, and physical performance was reflected by 6-meter walk speed. The Asian Working Group for Sarcopenia (AWGS) 2019 criteria were used to diagnose sarcopenia. Light physical activity (LPA) duration, moderate-to-vigorous physical activity (MVPA) duration, and total physical activity volume were calculated. A total of 3326 residents aged ≥60 years with complete data were selected as the survey participants. Multiple logistic regression models and restricted cubic splines (RCS) were used to assess the association between PA duration/volume and sarcopenia. Results In 10 provinces (autonomous regions) of China, the prevalence of sarcopenia in the elderly aged 60 years and above was 5.5% (95%CI: 4.7%, 6.2%). The logistic regression analysis showed that compared with the elderly reporting 0-7.0 h·week⁻¹ in LPA duration, the risk of sarcopenia in the elderly with LPA duration of >14.0-21.0 h·week⁻¹ was reduced by 51% (OR=0.49, 95%CI: 0.26, 0.96). Compared with the elderly with total physical activity ≥15.0 metabolic equivalent of task (MET)-h·week⁻¹, those with <7.5 MET-h·week⁻¹ had a 2.24-fold increased risk of sarcopenia (OR=2.24, 95%CI: 1.17, 4.29). The RCS results found that LPA duration and total physical activity volume each showed a nonlinear dose-response relationship with the risk of sarcopenia (P_overall<0.05, P_non-linear<0.05). Compared with the elderly with an LPA duration of 0 h· week⁻¹, the risk of sarcopenia in the elderly with an LPA duration of 12.6 h· week⁻¹ was the lowest (OR=0.42, 95%CI: 0.21, 0.83). Compared with the elderly with a total physical activity volume of 15.0 MET-h· week⁻¹, the elderly with a total physical activity volume of 46.0 MET-h· week⁻¹ had the lowest risk of sarcopenia (OR=0.57, 95%CI: 0.38, 0.84). There was no statistically significant association between weekly MVPA duration and the risk of sarcopenia (P>0.05). Conclusion Increasing weekly LPA duration and total physical activity volume would help to reduce the risk of sarcopenia.

Background Indoor air quality directly affects people's health, especially the impact of chemical pollutants in residential indoor air on children and the elderly is more significant. Objective To understand the pollution status of common chemical pollutants in residential indoor air in Shijiazhuang, evaluate the health risks of chemical pollutants to school-age children and the elderly, and provide reference for controlling indoor pollution in residential environment. Methods Using stratified random sampling, a total of 60 households were selected from 2 urban areas and 1 surrounding rural area in Shijiazhuang City, specifically in July 2023 (non-heating season) and December 2023 (heating season), respectively. Relevant data was collected through on-site sampling [including CO, CO₂, PM₁₀, PM_2.5, NO₂, SO₂, O₃, ammonia, formaldehyde, benzene, toluene, xylene, total volatile organic compounds (TVOC), trichloroethylene, and tetrachloroethylene] and survey questionnaires. The pollutant concentrations were evaluated following the Standards for indoor air quality of GB/T 18883-2022, and the inhalation exposure risks of the target population were assessed based on the health risk assessment method. Results In the indoor air of the urban and rural residence in Shijiazhuang City, except for CO, NO₂, SO₂, toluene, and xylene, which did not exceed the standard limits, other pollutants showed varying degrees of exceedance. The non-qualified rates of PM₁₀, PM_2.5, and CO₂ in the urban areas were higher than those in the rural areas (P < 0.05). The seasonal difference analysis showed that the non-qualified rates of PM_2.5, PM₁₀, CO₂, trichloroethylene, and tetrachloroethylene in the urban areas were higher in the heating season than in the non-heating season (P<0.05); the non-qualified rates of ammonia and formaldehyde in the rural areas increased significantly in the non-heating season(P<0.05). The health risk assessment indicated that the maximum hazard quotient (HQ) of tetrachloroethylene for the elderly exceeded 1, while the HQ values for ammonia, formaldehyde, benzene, toluene, xylene, and trichloroethylene remained below 1 for either children or the elderly. For carcinogenic risks, the median carcinogenic risk (CR) of formaldehyde for school-aged children or the elderly fell within the range of 10⁻⁶-10⁻⁴, whereas the median CR values for benzene, trichloroethylene, and tetrachloroethylene were all below 10⁻⁶. Conclusion The primary indoor air pollutants exceeding the national standard limits in residential areas of Shijiazhuang City include CO₂, PM₁₀, TVOC, PM_2.5, formaldehyde, ammonia, trichloroethylene, and tetrachloroethylene. The levels of these pollutants exhibit significant urban-rural and seasonal variations. Special attention should be paid to the non-carcinogenic risk of tetrachloroethylene to the elderly and the carcinogenic risks of formaldehyde to school-age children and the elderly.

Objective: To analyze the features of unhealthy lifestyle patterns among primary and secondary school students in the nutrition improvement program for rural compulsory education students (NIPRCES) areas in China in 2021 and 2023, so as to provide data support for lifestyle promotion and healthy development among primary and secondary school students. Methods: Adopting a cluster random sampling method, data on primary and secondary students aged 7-15 years from nutrition and health surveillance of China NIPRCES in 2021 and 2023 were collected. The prevalence of unhealthy lifestyles among primary and secondary students such as physical inactivity, outdoor inactivity, excessive screen time, and sleep deprivation by gender, school section, urban/rural, and region were analyzed. The reporting rates of the above indicators among primary and secondary students were compared by Chi-square test. Results: In 2021 and 2023, the rates of moderate to vigorous physical inactivity among primary and secondary school students were 79.2% and 80.4%, the rates of outdoor inactivity were 42.8% and 49.3%, the rates of excessive video time were 2.6% and 2.9%, the rates of sleep deprivation were 32.9% and 22.6%, and the differences were statistically significant( χ 2=51.86,1 071.48,18.36,3 296.99, P <0.05). In 2023, the rate of outdoor inactivity for primary and secondary students increased by 6.5 percentage points compared with 2021, and the rate of sleep deprivation decreased by 10.3 percentage points compared with that in 2021. In 2021 and 2023, the reporting rates of moderate to vigorous physical inactivity, outdoor inactivity, and sleep deprivation among girls and junior high school students were higher than those among boys ( χ 2=174.41,180.11; 175.75, 85.46 ;92.22,151.35) and elementary school students ( χ 2=136.64,5.75; 40.55,4.71;162.80,3 291.61); the reporting rates of moderate to vigorous physical inactivity( χ 2=194.43,118.60) and sleep deprivation ( χ 2=969.66,983.72) among urban students were higher than those among rural students; the reporting rates of excessive video time for boys and junior high school students were higher than those for girls ( χ 2=103.62,84.85) and elementary school students ( χ 2=810.09,626.51)( P <0.05). From a regional distribution perspective, the reporting rates of moderato to vigorous physical inactivity, outdoor inactivity, and excessive video time among primary and seconday school students in the central and western regions were lower than those in the eastern region ( χ 2= 663.44,302.78; 356.97,82.10;50.89,81.83) ( P <0.05). Conclusions Unhealthy lifestyles remain prevalent among primary and secondary students in NIPRCES areas of China. These findings underscore the need to strengthen policy implementation for promoting healthy lifestyles among primary and secondary school students.

Objective: To understand the prevalence of elevated blood pressure and its association with dietary patterns in children and adolescents in China, providing evidence for developing dietary intervention of hypertension in children and adolescents. Methods: Data were derived from the China Children s Nutrition and Health System Survey and Application Project(2019-2021). A stratified cluster random sampling method was used to include 7 933 participants from 28 survey sites in seven major regions of Northeast, North, Northwest, East, Central, South and Southwest China. Multivariate Logistic regression models were used to analyze associations between demographic characteristics, nutritional status and elevated blood pressure. Exploratory factor analysis identified dietary patterns, which were divided into three quartile groups (T3, T2, T1) based on factor scores (compliance for dietary pattern) from high to low, and multivariate Logistic regression model assessed the correlation between elevated blood pressure and dietary patterns. Results: The prevalence of elevated blood pressure was 15.4% among Chinese children aged 7-17 years. Significant differences were observed across nutritional status (reference: underweight; normal weight: OR =1.57; overweight: OR = 2.61 ; obesity: OR =3.85), urban/rural residence (reference: rural; urban: OR =0.86), and paternal education (reference: junior high school and below; bachelor degree or above: OR =0.68) ( P <0.05). The detection rates of high blood pressure in T3 group children and adolescents with four dietary patterns (staple food, animal based food, snacks, vegetables and fruits) were 15.7%, 14.6%, 16.8%, and 15.8%, respectively. After adjusting for residence, paternal education, and nutritional status, the "snack dietary pattern" (mainly candy, sugar sweetened beverages, and processed snacks) showed positive associations with elevated blood pressure in T2 ( OR =1.21) and T3 ( OR =1.19) tertiles ( P <0.05). Conclusions The snack dietary pattern is a related factor for elevated blood pressure in children and adolescents. Restricting unhealthy snack intake may promote cardiovascular health.

Objective: To explore the association between CDKAL1 rs35261542, FAIM2 rs 3205718, and VGLL4 rs 2574704 polymorphisms with childhood obesity and related metabolic phenotypes to provide evidence for personalized prevention and management strategies. Methods: Based on the 2023 Long term Nutritional Health Effects of Early Childhood Nutrition Package Intervention project, the study enrolled 1 078 children aged 5-7 years from four counties in Henan (Songxian and Ruyang countries) and Guizhou (Guiding and Fuquan countries) provinces. Using BMI Z scores, 87 overweight and obese(OVOB) children were selected and matched by sex, age, and BMI Z score with 117 normal weight controls. Participants were further stratified into four metabolic phenotype groups: metabolically healthy normal weight (MHNW, n =51), metabolically unhealthy normal weight (MUNW, n =66), metabolically healthy obesity (MHO, n =31) and metabolically unhealthy obesity (MUO, n =56) based on four conventional cardiometabolic risk factor (CR) criteria. Data were collected through questionnaires, anthropometric measurements, serum biochemical tests, and KASP genotyping. The distribution of three genetic polymorphisms ( CDKAL1 rs35261542, FAIM2 rs3205718, VGLL4 rs 2574704) across metabolic subgroups was analyzed. Multivariate Logistic regression models assessed associations between these polymorphisms and obesity/metabolic phenotypes. Results: Multivariate Logistic regression analysis showed that Homozygous mutant AA genotype of CDKAL1 rs 35261542 was positively associated with OVOB( OR =3.63), MHO ( OR =11.04), MUO ( OR = 4.88 ) ( P <0.05). Homozygous TT genotype of FAIM2 rs 3205718 increased OVOB risk ( OR =4.44, P <0.05) but showed no association with metabolic phenotypes ( P >0.05). Homozygous mutant TT of VGLL4 rs 2574704 reduced the risks of MHO and MUO ( OR = 0.30, 0.24， P <0.05). Cumulative genetic effects analysis demonstrated carriers of 1 or 2 risk genotypes of rs 35261542 and rs 3205718 had progressively higher OVOB risk ( OR =2.53, 20.79), and the combination of rs 35261542 and rs 2574704 increased risks for both MHO ( OR =8.50) and MUO ( OR =5.00) ( P <0.05). Conclusions The AA genotype of rs 35261542 ( CDKAL1 ) positively correlates with childhood obesity and metabolic abnormalities. The TT genotype of rs 3205718 ( FAIM 2) increases obesity risk but not metabolic phenotypes. The TT genotype of rs 2574704 ( VGLL 4) shows protective effects against metabolic dysfunction. Risk genotypes exhibit dosedependent cumulative effects on obesity and metabolic outcomes.