Height changes among students under the National Nutrition Improvement Program for Rural Compulsory Education Students during 2012-2017

Objective To analyze the height changes among children who had received subsidies of the National Nutrition Improvement Program for Rural Compulsory Education Students (NNIPRCES) by comparing data from the year of 2012 and 2017. Methods Among 699 counties where NNIPRCES was implemented, at least 10% of elementary schools and primary middle schools with different food supply modes (school canteen meals, company meals, and mix meals) in the county were selected randomly. Forty students from one or two classes from each grade (grade 1 to grade 9) were randomly selected, to ensure equal proportion of boys and girls in each grade were surveyed, data on height from 1 655 793 students measured in 2012 were compared with 1 419 281 students measured in 2017. Height was measured by metal height pole within 0.1 cm accuracy. Results From 2012 to 2017, the average increase of height in boys and girls aged 6-15 years was 1.9 and 2.0 cm, respectively. Among them, maximum increment was found in boys at the age of 13 years and in girls at the age of 12 years, respectively, which was 3.0 and 2.8 cm. The average increase in boys from the central and western region was 2.1 and 2.2 cm, respectively, while increase in girls from the central and western region was both 2.2 cm. Compared with the results from 2012, height of boys with the 5 th, 50 th and 95 th height percentiles in 2012 increased by 1.7, 2.0 and 2.1 cm, respectively in 2017, while the increase in girls was 2.1, 2.0 and 2.2 cm, respectively. The average increment of western students with the 5 th and 95 th height percentiles was higher than those of students from the central region. Conclusion The average height of students has increased after the implementation of NNIPRCES. However, the development was unbalanced between the central and western region, which requires more targeted intervening strategies to improve the nutritional status of students.