Analysis On The Changes Of Nutritional Status And Influencing Factors Of Students In The "Nutrition Improvement Program For Rural Compulsory Education Students" In 2012-2017

Objective:Using the monitoring data of primary and secondary school students in the key monitoring counties in 2012-2017 in the "Nutrition Improvement Program for Rural Compulsory Education Students(NIPRCES)",we will explore the changes in the nutritional status of students and the influencing factors.And then we provide basic information and recommendations for improving the nutritional status of primary and secondary school students in rural areas of the central and western regions in China and further implementation of this student nutrition improvement program.Methods:Using multi-stage stratified random cluster sampling method,in the 50 NIPRCES key monitoring counties,according to three food supply modes:school-based,company-based and others,primary and junior high schools with a random selection of no less than 10%were regular schools,and 2 primary schools and 2 junior high schools were selected as key schools from these schools;and 1-2 classes were randomly selected each grade to ensure that the number of students participating in the monitoring reached 40 or so,with equal number of genders.From 2012 onwards,questionnaires and physical measurements would be conducted for counties,schools and students at each survey site around September each year.In this study,students from key monitoring counties with 2 or more monitoring data between 2012 and 2017 were included,and a total of 356,387 individual students were screened.The intervention in this study was dietary subsidy from the Ministry of Finance,3 yuan per student per day,which increased to 4 yuan from November 2014.Collecting information from counties,schools,and students using standardized questionnaires;using uniform devices to measure the height and weight of the students,the nutritional status of the students were determined by age-specific height and BMI as malnutrition(including stunting and wasting)and overweight/obesity(including overweight and obesity).Data were collated and analyzed using SAS 9.4 and MLwiN2.36.Using variance component model of random coefficients and logistic regression model of random coefficients to analyze the influencing factors of students’nutritional status.Results:A total of 356,387 students’ longitudinal monitoring data were collected in this study,each student had two or more monitoring data.From 2012 to 2017,the proportion of male students was between 51.7%and 52.4%,and that of female students was between 47.6%and 48.3%.The proportion of students in the central region was between 36.4%and 47.7%,and that in the western region was between 52.3%and 63.6%.The number of students in the central region was lower than that in the western region.The proportion of the lower primary school group(grade one～three)fell from 57.2%to 32.5%,the proportion of the primary school senior group(grade four～six)increased from 32.5%to 52.7%,the junior high school group accounted for 10.3%-15.5%.In 2012-2017,the height,weight and BMI of students increased with time,and the stunting rate of students decreased from 6.66%in 2012 to 4.24%in 2017.The malnutrition rate decreased from 16.60%to 14.15%,both of which showed a downward trend with time,while the rate of wasting did not change with time.The overweight rate of students increased from 7.14%in 2012 to 8.07%in 2017,the obesity rate increased from 2.40%to 3.74%,and the overweight/obesity rate increased from 9.54%to 11.81%in total,all of which showed a upward trend with time.The malnutrition rate of students in adolescents and western regions and boys were higher.The overweight/obesity rate of lower age,central regions and boys were higher.The nutritional status of students in different provinces varied with time.Through multi-factor analysis,it is found that the student’s dietary subsidy is 4 yuan,the county has local subsidies or other nutritional improvement measures,the school adopts the company-based feeding mode and provides class-interval meal,and the school canteen uses electronic catering software,to provide breakfast and staple food in breakfast,the school has health education classes and charge for meals;students’ parents do not go out of town to work,students who have a higher frequency of weekly milk consumption and a higher nutritional knowledge score,have a lower risk of malnutrition.There are other nutrition improvement measures in the county,the school provides a company-based or mixed feeding mode,the school provides a free dinner or some food in the dinner,the school has a canteen,and the breakfast provides meat and eggs and fruit,and other nutritional improvements;students’ mothers work outside of town,students who are boarding at school,eating eggs 1-6 times a week,drinking 1-6 times a week,and eating snacks more frequently every day have a lower risk of overweight and obesity.Conclusion:After the implementation of the NIPRCES,the physical and nutritional status of students have been improved to some extent,but the differences among different groups of students vary with time.The nutritional status of students is significantly affected by gender,age and region.Therefore,it is necessary to pay attention to the susceptible population of malnutrition and overweight/obesity.company-based feeding mode,3 kinds of food delivery forms,school canteen construction,using electronic catering software,canteen for breakfast,breakfast for meat and eggs,county and school take other forms of nutrition improvement measures,students with higher nutritional knowledge scores,higher frequency of egg and milk intake,outdoor activities for 1 hour and above,and parents do not work out of town have a lower risk of malnutrition and overweight/obesity.