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Changes in anthropometric indices among Korean school students based on the 2010 and 2018 Korea School Health Examination Surveys

Article information

Ann Pediatr Endocrinol Metab. 2021;26(1):38-45
Publication date (electronic) : 2021 March 31
doi : https://doi.org/10.6065/apem.2040100.050
Department of Pediatrics, Inje University Sanggye Paik Hospital, Seoul, Korea
Address for correspondence: Mi Jung Park Department of Pediatrics, Inje University Sanggye Paik Hospital, 1342 Dongil-ro, Nowon-gu, Seoul 01757, Korea Email: pmj@paik.ac.kr
Address for co-correspondence: Shin-Hye Kim Department of Pediatrics, Inje University Sanggye Paik Hospital, 1342 Dongil-ro, Nowon-gu, Seoul 01757, Korea Email: s2635@paik.ac.kr
Received 2020 May 19; Revised 2020 June 16; Accepted 2020 June 28.

Abstract

Purpose

This study sought to identify changes in anthropometric values among Korean school students by comparing the most recent nationwide data with previous data.

Methods

Data from the Korea School Health Examination Survey 2018 were used. The study population consisted of 107,954 Korean school students ranging from the 1st grade in elementary school through the 3rd year of high school. The difference in height and weight values for each sex and school grade was analyzed by comparison with the Korea School Health Examination Survey 2010.

Results

The mean heights of the 3rd-year high school students were 173.8 cm and 160.9 cm for boys and girls, respectively. The mean height of the 3rd-year high school students showed no difference between 2010 and 2018 for either sex. However, the mean height of the age group from the 3rd grade in elementary school through the 1st year in high school was significantly taller in 2018 compared to 2010 for both sexes. The mean weights of the 3rd-year high school students were 71.3 kg and 57.5 kg for boys and girls, respectively. The mean weight of students in 2018 was significantly higher compared to students in 2010 for most school grades.

Conclusions

Although no significant change was found in near-final height between 2010 and 2018 among high school seniors, the mean height during the growth spurt was significantly higher in 2018 compared to 2010. Weight was significantly higher in almost all school grades in 2018 compared to 2010.

Highlights

For Korean school students, the near-final height showed no difference between 2010 and 2018. The mean height during the growth spurt was higher in 2018 than in 2010. The mean weight was higher in almost all school grades in 2018 than in 2010.

Introduction

The linear growth status of pediatric adolescents undergoing a period of growth is the most basic and essential indicator of their overall health status [1]. Since 1967, the Korean National Growth Charts (KNGC) have been updated every 10 years based on data from the National Anthropometric Survey [2]. Due to consistent reports on the ongoing trends of early pubertal development among Korean adolescents, the 10-year interval for publishing growth charts might be relatively delayed in reflecting the current status of anthropometric indices in Korean adolescents [3,4]. For 3- to 18-year-old children and adolescents, the KNGC 2017 was obtained using National Anthropometric Survey data from 1997 and 2005 [5]. Therefore, the KNGC 2017 may be limited in accurately reflecting the physical growth of the current Korean pediatric population.

In Korea, all students elementary through high school undergo a mandatory annual measurement at schools or at hospitals under the supervision of the Ministry of Education and the Korea Educational Environments Protection Agency. Additionally, the collected data are subsumed under the Korea School Health Examination Survey (KSHES) [6].

This study aimed to analyze the height, weight, and body mass index (BMI) of current Korean school students using the recently released KSHES 2018. We also compared the height and weight in the KSHES 2018 with measurements from the KSHES 2010 to investigate the change in body physique among Korean school students.

Materials and methods

1. Study population

The latest nationally representative data from the Korea School Health Examination Survey 2018 (1,023 schools including 108,016 Korean students from the 1st grade in elementary school through the 3rd year of high school; http://www.schoolhealth.kr/) were used [6]. The Ministry of Education conducts annual anthropometric measurements (height and weight) and health examinations (vision, hearing, blood pressure, urinalysis, blood analysis, chest radiography, etc.) for students in selected grades (the 1st and 4th grade in elementary school, the 1st year in middle school, and the 1st year in high school) every year to assess the health status of Korean school students following Article 7 of the School Health Act. These students visit medical institutions between April and July for health check-ups [6]. The school staff measures the height and weight of the other students who are exempted from the health check-up every year [6]. Using the National Education Information System, the results for each school are submitted to the Ministry of Education. Notably, the sample school provided 99.7% raw data in 2018 [6]. The data generated through this process are government-designated statistics (approval number: 112002) based on Article 17 of the Statistics Act [6].

This study used the publicly available data from the KSHES 2018. Of the entire study population, students whose weights were above the range created by the mean +5× standard deviation by sex and height (n=62) were excluded. The final study population comprised 107,954 Korean students from the 1st grade in elementary school through the 3rd year of high school. The KSHES 2010 result report (747 schools including 188,352 Korean students from the 1st grade in elementary school through the 3rd year of high school; http://www.schoolhealth.kr/) was used to compare against the 2018 students' physiques.

2. Anthropometric measurements

Height (cm) was measured from the soles of the feet, after removing the shoes and placing the heels together, to the top of the student’s head, with the back, hip, and heels firmly positioned against the vertical backboard of the stadiometer. In the upright position, arms were placed on the sides of the body, and eyes and ears remained in a horizontal position. Weight (kg) was measured while wearing light clothes without shoes on a digital scale with an accuracy of 0.1 kg [6]. The BMI was calculated by dividing the weight (kg) by the square of the height (m).

3. Statistical analysis

IBM SPSS Statistics ver. 21.0 (IBM Co., Armonk, NY, USA) was used for performing statistical analyses. The sample data in the dataset were weighted for all statistical analyses. The values of the variables are presented as mean±standard error or numbers (weighted percentages). The complex samples crosstabs procedures were used for analyzing categorical variables, and the complex samples descriptive procedures were used for analyzing continuous variables. To analyze the mean values of height, weight, and BMI, the complex samples general linear models were used. The frequencies procedure was used to obtain summary measures for the selected percentile values of height, weight, and BMI, according to sex and school grade. An independent samples t-test was used to compare the mean height and weight between participants in the KSHES 2010 and 2018. A P-value of <0.05 was considered statistically significant.

Results

1. General characteristics

Table 1 presents the weighted distribution of the participants’ general characteristics. Participants included 107,954 Korean students from the 1st grade in elementary school through the 3rd year in high school. The mean age of the overall study population was 11.9±0.00 years, and boys accounted for 51.8% of the study population. The regional distributions of urban (major cities), suburban (small and medium-sized cities), and rural (small towns) areas were 83.6%, 5.9%, and 10.5%, respectively.

General characteristics of the study subjects (n=107,954)

2. Percentile values of height according to sex and school grade

Table 2 presents the mean and percentile values of height according to sex and school grade. The 50th percentile values of the height of 6th-grade elementary school boys and girls were 151.9 cm and 152.4 cm, respectively. The 50th percentile values of the height of 3rd-year high school boys and girls were 173.7 cm and 160.8 cm, respectively. The 3rd percentile values of height, which are associated with short stature designation, were 162.9 cm and 151.0 cm for 3rd-year high school boys and girls, respectively [5]. The steepest change in the median height was observed for boys between the 6th grade in elementary school and the 1st year of middle school (8.6 cm/yr increase) and for girls between the 5th and 6th grades of elementary school (6.7 cm/yr increase).

Mean and percentile values of height by sex and school grade in Korean school students

3. Percentile values of weight according to sex and school grade

Table 3 presents the mean and percentile values of weight by sex and school grade. The 50th percentile values of the weight of 6th-grade elementary school boys and girls were 47.7 kg and 44.8 kg, respectively. The 50th percentile values of the weight of 3rd-year high school boys and girls were 68.9 kg and 55.8 kg, respectively.

Mean and percentile values of weight by sex and school grade in Korean school students

4. Percentile values of BMI according to sex and school grade

Table 4 presents the mean and percentile values of BMI according to sex and school grade. The 50th percentile values of BMI of 6th-grade elementary school boys and girls were 20.5 kg/m2 and 19.2 kg/m2, respectively. The 50th percentile values of BMI of 3rd-year high school boys and girls were 22.8 kg/m2 and 21.6 kg/m2, respectively. The 5th percentile values of BMI, which are associated with underweight status, were 18.0 kg/m2 and 17.5 kg/m2 for 3rd-year high school boys and girls, respectively [5]. The 85th percentile values of BMI, which are associated with overweight, were 27.7 kg/m2 and 25.8 kg/m2 for 3rd-year high school boys and girls, respectively [5]. The 95th percentile values of BMI, which are associated with obesity, were 31.9 kg/m2 and 29.6 kg/m2 for 3rd-year high school boys and girls, respectively [5].

Mean and percentile values of body mass index by sex and school grade in Korean school students

5. Comparison of height and weight values according to sex and school grade between KSHES 2010 and 2018

Table 5 and Fig. 1 present the comparison of mean height and weight values between KSHES 2010 and 2018. The mean height values of students between the 3rd grade in elementary school and the 1st year in high school were significantly higher in 2018 compared with those in 2010, in both sexes. In boys, the grade that showed the greatest height gap was the 1st year of middle school, where the difference in mean height values was 2.5 cm (P<0.0001). In girls, the grade that showed the greatest height gap was also the 1st year of middle school, where the difference was 1.4 cm (P<0.0001). Additionally, the mean weight values of the study population for most school grades in 2018 were significantly higher than those in 2010 among both boys and girls (P<0.05).

Comparison of mean height and weight by sex and school grade between Korea School Health Examination Survey (KSHES) 2010 (n=188,352) and 2018 (n=107,954)

Fig. 1.

Comparisons of mean height and weight of Korean school students by sex and school grade between Korea School Health Examination Surveys (KSHES) from 2010 and 2018. (A) Mean height for boys, (B) mean weight for boys, (C) mean height for girls, and (D) mean weight for girls. Es, elementary school; Gr, grade; Ms, middle school; Hs, high school. *P<0.05. **P<0.001.

Discussion

This study presented the mean and selected percentile values of height, weight, and BMI of Korean school students based on data from the most recent large-scale measurement. In 2018, the mean height among students between the 3rd grade in elementary school and the 1st year in high school was significantly taller than those in 2010 for both sexes. The mean heights of the 3rd-year high school students in 2018 were 173.8 cm and 160.9 cm for boys and girls, respectively. No significant differences in the mean heights of 1st and 2nd graders in elementary school and seniors in high school were found between 2010 and 2018 for either sex. Meanwhile, the mean weight in 2018 was significantly higher than in 2010 for most school grades.

The mean heights of the 3rd-year high school students in 2018, 173.8 cm for boys and 160.9 cm for girls, were found to be similar to those in 2010. However, the mean height of the age group from the 3rd grade in elementary school through the 3rd year in middle school was significantly taller in 2018 than in 2010, showing differences of about 2 cm for boys and 1 cm for girls. This result suggests that the heights during the rapid growth period are taller than in the past, while near-final height values are similar to those of the past.

A previous study revealed a significant increment in the mean height among the Korean pediatric population between 1965 and 2005 [7]. However, another study demonstrated stabilized trends in the near-final height of Korean adolescents after comparing the Korean national anthropometric data in 2005 and 2010 [8]. The increase in the height of pediatric adolescents has reportedly slowed down in most developed countries from the end of the 20th century since the rapid economic growth has ceased and the overall living environment has stabilized [7,9,10]. Our study results are consistent with the previous study, indicating no significant changes in near-final height over the past decade, similar to other developed countries [7,9,10].

While there is little difference in the mean height values between 2010 and 2018 in the younger age groups, a significant difference was observed beginning from the 6th grade in elementary school for boys and the 4th grade in elementary school for girls. The growth spurt is followed by the appearance of secondary sexual characteristics during puberty [11]. Therefore, consistent with several previous epidemiological studies, our findings reflect the accelerated timing of puberty and the growth spurt among Korean school students in recent decades [3,4,11-14].

The mean weight in 2018 was found to be significantly higher compared to 2010 in both sexes through all of the school grades, except for 1st-grade elementary school boys. This finding suggests that the rapid increase in the mean weight of the Korean pediatric population, which has been observed since the 1980s, continues into 2018 [7].

In the present study, the 50th percentile values of BMI of the 3rd-year high school students were 22.8 kg/m2 and 21.6 kg/m2 for boys and girls, respectively. On the other hand, the 50th percentile values of BMI for the same age group in the KNGC 2017, about 22.3 kg/m2 in boys and about 21.0 kg/m2 in girls, were approximately 0.5 kg/m2 lower than those in the current study population [5]. In this study, the 95th percentile values of BMI were 31.9 kg/m2 and 29.6 kg/m2 for 3rd-year high school boys and girls, respectively. These values exceeded the BMI 99th percentile values for adolescents in the same age group in the KNGC 2017 (28.9 kg/m2 in boys and 27.7 kg/m2 in girls) [5]. This finding indicates an increasing prevalence of extreme obesity among Korean school students, especially among older students.

This study has certain limitations. First, although the Ministry of Education and the Korea Educational Environments Protection Agenc y provided a st and ard proto col for anthropometric measurements, measurement bias may exist since the measuring devices were not standardized. Second, the survey did not include questionnaires on pubertal signs. Third, due to the absence of BMI reference values in the KSHES 2010 result report, we could not compare the BMI values between the 2 datasets in this study. Nevertheless, the strength of this study is that it was based on the most recent, large-scale, and valid measurements of anthropometric indices.

In conclusion, this study demonstrated the current status of anthropometric index measurements among Korean school students based on the latest large-scale data in 2018 and also compared them with previous data from 2010.

No difference in height was observed between 2010 and 2018 for 3rd-year high school students, although height values were significantly higher in 2018 than in 2010 among school students undergoing a rapid growth period. Meanwhile, weight values in 2018 were significantly higher than in 2010 in nearly all of the school grades. Therefore, the KSHES might be useful in providing consistently crucial information of anthropometric indices to modify and establish the KNGC in the future.

Notes

Ethical statement

This study was approved by the Institutional Review Board (IRB) of the Inje University Sanggye Paik Hospital (approval number: SGPAIK 2020-02-002). The data are government-designated statistics (approval number: 112002) based on Article 17 of the Statistics Act.

Conflicts of interest

No potential conflict of interest relevant to this article was reported.

Acknowledgements

We are grateful to the Ministry of Education of South Korea for permission to use the KSHES data. This study is based on the KSHES, which was conducted by the Ministry of Education with funding from the Government of Korea.

References

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Article information Continued

Fig. 1.

Comparisons of mean height and weight of Korean school students by sex and school grade between Korea School Health Examination Surveys (KSHES) from 2010 and 2018. (A) Mean height for boys, (B) mean weight for boys, (C) mean height for girls, and (D) mean weight for girls. Es, elementary school; Gr, grade; Ms, middle school; Hs, high school. *P<0.05. **P<0.001.

Table 1.

General characteristics of the study subjects (n=107,954)

Characteristic Mean±SE No. (%*)
Age (yr) 11.9±0.00
School grade (yr)
 Elementary school
  Grade 1 6.4±0.01 6,437 (8.2)
  Grade 2 7.3±0.01 6,537 (8.1)
  Grade 3 8.4±0.01 6,532 (7.7)
  Grade 4 9.4±0.01 6,556 (8.1)
  Grade 5 10.3±0.01 6,564 (8.5)
  Grade 6 11.4±0.01 6,465 (7.9)
 Middle school
  Grade 1 12.4±0.01 9,823 (7.5)
  Grade 2 13.4±0.01 10,002 (8.1)
  Grade 3 14.4±0.01 10,325 (8.4)
 High school
  Grade 1 15.4±0.01 12,027 (8.2)
  Grade 2 16.3±0.01 12,944 (9.1)
  Grade 3 17.3±0.01 13,742 (10.2)
Sex
 Boys - 55,039 (51.8)
 Girls - 52,915 (48.2)
Residential area
 Urban - 83,680 (83.6)
 Suburban - 8,431 (5.9)
 Rural - 15,843 (10.5)

SE, standard error.

*

Weighted percentages after accounting for the sampling design.

Table 2.

Mean and percentile values of height by sex and school grade in Korean school students

School grade No. Mean±SE Difference* Percentile values of height (cm)
1st 3rd 5th 10th 15th 25th 50th 75th 85th 90th 95th 97th 99th
Boys
Elementary school
Grade 1 3,299 122.1±0.1 - 110.1 112.6 114.0 115.8 116.9 118.5 121.8 125.3 127.3 128.4 130.5 132.1 135.4
Grade 2 3,357 127.8±0.1 5.7 115.5 118.0 119.2 121.0 122.2 124.0 127.8 131.4 133.3 134.7 137.0 138.3 141.1
Grade 3 3,383 133.8±0.1 6.0 120.4 123.2 124.4 126.4 127.8 129.8 133.7 137.6 139.7 141.2 143.4 145.0 148.0
Grade 4 3,355 139.7±0.1 5.9 126.2 128.8 130.0 131.9 133.3 135.4 139.4 143.6 145.9 147.9 150.3 152.1 154.8
Grade 5 3,384 145.0±0.1 5.3 130.0 132.7 134.2 136.5 138.0 140.0 144.3 148.8 151.2 153.2 156.0 158.0 161.9
Grade 6 3,333 152.2±0.1 7.2 135.9 138.8 140.5 142.8 144.5 147.0 151.9 157.0 160.3 162.1 165.0 167.0 170.5
Middle school
Grade 1 5,038 160.4±0.1 8.2 141.5 145.0 147.2 150.0 151.8 154.9 160.5 166.0 168.5 170.1 172.7 174.3 177.4
Grade 2 5,102 166.3±0.1 5.9 147.6 151.6 153.6 156.7 158.8 161.7 166.5 170.8 173.2 174.9 177.1 178.6 181.7
Grade 3 5,315 170.2±0.1 3.9 154.2 157.4 159.5 162.3 164.0 166.1 170.3 174.2 176.3 178.0 180.1 181.5 184.4
High school
Grade 1 6,188 172.6±0.1 2.4 159.0 161.5 162.8 165.2 166.6 168.7 172.4 176.4 178.5 180.0 182.1 183.7 186.3
Grade 2 6,448 173.3±0.1 0.7 159.3 162.4 164.0 165.9 167.2 169.3 173.1 177.0 179.3 180.8 183.0 184.6 187.4
Grade 3 6,837 173.8±0.1 0.5 160.4 162.9 164.3 166.3 167.8 169.9 173.7 177.6 179.8 181.1 183.1 184.6 187.1

Girls
Elementary school
Grade 1 3,138 120.9±0.1 - 109.7 111.7 112.7 114.5 115.6 117.4 120.8 124.2 126.4 127.7 129.8 131.2 134.1
Grade 2 3,180 126.8±0.1 5.9 114.4 117.0 118.0 120.0 121.3 123.0 126.6 130.1 132.2 133.4 135.5 137.2 140.5
Grade 3 3,149 132.4±0.1 5.6 119.1 121.6 123.3 125.2 126.5 128.5 132.4 136.2 138.6 139.9 142.2 144.0 146.8
Grade 4 3,201 139.1±0.1 6.7 125.7 127.7 128.9 131.0 132.5 134.6 139.0 143.4 145.9 147.8 150.4 152.3 154.8
Grade 5 3,180 145.6±0.1 6.5 130.1 133.0 134.4 136.7 138.1 140.6 145.7 150.4 153.1 154.7 157.1 158.4 161.0
Grade 6 3,132 152.2±0.1 6.6 136.7 139.7 141.3 143.9 145.7 148.1 152.4 156.6 158.6 160.2 162.2 163.3 166.2
Middle school
Grade 1 4,785 156.9±0.1 4.7 142.9 146.2 147.6 150.0 151.4 153.3 157.0 160.4 162.5 163.9 166.0 167.5 169.6
Grade 2 4,900 158.9±0.1 2.0 146.5 149.0 150.2 152.2 153.5 155.4 158.9 162.4 164.4 165.7 167.7 169.0 171.3
Grade 3 5,010 160.3±0.1 1.4 147.8 150.2 151.7 153.3 154.7 156.5 160.1 163.8 165.9 167.2 169.3 170.5 173.9
High school
Grade 1 5,839 160.9±0.1 0.6 148.5 151.0 152.2 154.0 155.3 157.2 160.8 164.3 166.2 167.5 169.5 170.8 173.3
Grade 2 6,496 160.9±0.1 0.0 148.3 151.0 152.5 154.2 155.6 157.4 160.8 164.4 166.2 167.5 169.6 171.0 173.4
Grade 3 6,905 160.9±0.1 0.0 148.3 151.0 152.3 154.0 155.3 157.2 160.8 164.4 166.4 167.8 170.0 171.0 173.4

SE, standard error.

*

Difference values are the mean differences in height between the corresponding grade-students and the 1-year younger grade-students.

Table 3.

Mean and percentile values of weight by sex and school grade in Korean school students

School grade No. Mean±SE Difference* Percentile values of weight (kg)
1st 3rd 5th 10th 15th 25th 50th 75th 85th 90th 95th 97th 99th
Boys
Elementary school
Grade 1 3,299 25.2±0.1 - 17.4 18.8 19.2 20.0 20.7 21.7 24.0 27.6 29.8 32.0 35.6 37.8 42.4
Grade 2 3,357 28.9±0.2 3.7 19.2 20.5 21.3 22.4 23.1 24.4 27.4 31.9 35.2 37.6 41.7 44.3 49.9
Grade 3 3,383 33.3±0.2 4.4 21.4 22.8 23.7 25.0 26.0 27.5 31.5 37.5 41.5 44.1 48.8 52.3 58.2
Grade 4 3,355 37.9±0.2 4.6 24.0 25.8 26.4 28.0 29.0 31.0 36.0 43.6 48.3 50.9 55.8 59.3 66.0
Grade 5 3,384 42.7±0.2 4.8 26.1 28.2 29.1 30.9 32.2 34.5 40.6 48.5 53.3 56.9 63.1 66.7 74.1
Grade 6 3,333 49.1±0.3 6.4 28.6 31.5 32.7 35.0 37.0 40.4 47.7 56.5 61.8 65.5 71.8 75.4 81.6
Middle school
Grade 1 5,038 54.6±0.2 5.5 31.8 34.9 36.7 39.8 42.0 45.2 52.7 62.7 68.0 72.0 78.1 82.5 92.0
Grade 2 5,102 60.7±0.3 6.1 36.0 39.9 41.7 44.9 47.3 50.8 58.3 68.5 75.4 79.6 87.2 92.0 102.0
Grade 3 5,315 64.6±0.2 3.9 40.9 44.4 46.2 49.2 51.3 54.6 62.2 72.4 79.1 84.0 92.2 98.0 108.5
High school
Grade 1 6,188 67.8±0.2 3.2 44.6 47.6 49.3 52.5 54.4 57.8 65.3 75.0 81.6 86.6 94.8 99.6 108.6
Grade 2 6,448 69.3±0.2 1.5 46.1 49.1 51.0 53.8 55.9 59.5 66.9 76.7 83.2 87.8 96.6 102.3 112.9
Grade 3 6,837 71.3±0.2 2.0 48.0 51.1 52.6 55.8 58.0 61.3 68.9 78.2 85.0 90.0 97.9 103.0 115.1

Girls
Elementary school
Grade 1 3,138 24.2±0.1 - 17.0 18.0 18.6 19.3 20.0 21.0 23.4 26.5 28.5 30.3 32.6 34.9 39.6
Grade 2 3,180 27.4±0.1 3.2 18.6 19.7 20.4 21.4 22.2 23.4 26.0 30.0 32.8 35.2 38.5 40.5 45.2
Grade 3 3,149 30.8±0.1 3.4 20.4 21.8 22.5 23.7 24.6 26.2 29.8 34.5 37.3 39.7 43.6 46.1 50.5
Grade 4 3,201 35.3±0.2 4.5 22.5 24.0 24.8 26.5 27.6 29.4 34.1 40.1 44.0 46.9 51.0 54.3 60.3
Grade 5 3,180 40.3±0.2 5.0 24.7 26.9 28.0 29.9 31.2 33.7 39.0 45.7 49.5 52.6 57.2 60.6 67.2
Grade 6 3,132 46.0±0.3 5.7 28.3 31.0 32.2 34.5 36.3 39.3 44.8 51.5 55.5 58.6 64.5 67.9 74.6
Middle school
Grade 1 4,785 50.4±0.2 4.4 32.3 35.4 36.9 39.2 40.8 43.5 49.0 55.8 60.3 64.1 70.6 74.4 80.6
Grade 2 4,900 53.2±0.2 2.8 36.0 38.5 40.0 42.2 44.0 46.3 51.9 58.2 63.0 67.0 73.1 77.1 87.0
Grade 3 5,010 55.4±0.2 2.2 38.9 41.1 42.5 44.3 45.9 48.1 53.4 60.0 64.8 68.4 75.0 79.6 88.8
High school
Grade 1 5,839 56.7±0.2 1.3 39.7 42.0 43.3 45.5 47.1 49.6 54.8 61.5 66.0 70.0 76.3 80.9 90.2
Grade 2 6,496 57.0±0.2 0.3 40.0 42.4 43.9 46.0 47.6 50.0 55.0 61.9 66.8 70.7 77.5 82.0 90.6
Grade 3 6,905 57.5±0.2 0.5 40.0 42.8 44.2 46.5 48.0 50.4 55.8 62.9 67.7 71.5 78.0 82.2 92.7

SE, standard error.

*

Difference values are the mean differences in weight between the corresponding grade-students and the 1-year younger grade-students.

Table 4.

Mean and percentile values of body mass index by sex and school grade in Korean school students

School grade No. Mean±SE Difference* Percentile values of body mass index (kg/m2)
1st 3rd 5th 10th 15th 25th 50th 75th 85th 90th 95th 97th 99th
Boys
Elementary school
Grade 1 3,299 16.8±0.1 - 13.0 13.6 13.9 14.4 14.6 15.1 16.2 18.0 19.2 20.3 22.1 23.4 25.2
Grade 2 3,357 17.5±0.1 0.7 13.2 13.8 14.1 14.6 15.0 15.5 16.7 18.9 20.6 21.8 23.4 24.8 26.6
Grade 3 3,383 18.5±0.1 1.0 13.3 14.0 14.4 15.0 15.3 15.9 17.7 20.4 22.0 23.3 25.3 26.5 28.9
Grade 4 3,355 19.3±0.1 0.8 13.8 14.4 14.8 15.3 15.8 16.5 18.5 21.6 23.2 24.5 26.4 27.5 30.1
Grade 5 3,384 20.1±0.1 0.8 14.0 14.8 15.2 15.8 16.3 17.1 19.4 22.5 24.4 25.5 27.4 28.8 30.9
Grade 6 3,333 21.0±0.1 0.9 14.5 15.1 15.6 16.3 16.9 17.9 20.5 23.7 25.5 26.6 28.4 29.6 32.0
Middle school
Grade 1 5,038 21.1±0.1 0.1 14.6 15.4 15.8 16.5 17.1 18.0 20.4 23.7 25.6 26.8 28.7 30.0 32.8
Grade 2 5,102 21.8±0.1 0.7 15.1 15.9 16.4 17.2 17.8 18.7 21.0 24.4 26.5 28.0 30.1 31.6 34.1
Grade 3 5,315 22.2±0.1 0.4 15.7 16.4 16.9 17.5 18.1 19.1 21.4 24.7 26.8 28.4 30.7 32.4 35.2
High school
Grade 1 6,188 22.7±0.1 0.5 16.0 16.8 17.3 18.0 18.6 19.6 21.9 25.1 27.1 28.6 30.9 32.5 35.6
Grade 2 6,448 23.0±0.1 0.3 16.1 17.0 17.5 18.3 19.0 20.0 22.3 25.2 27.3 29.0 31.3 33.2 36.4
Grade 3 6,837 23.6±0.1 0.6 16.7 17.5 18.0 18.8 19.4 20.5 22.8 25.8 27.7 29.3 31.9 33.7 37.0

Girls
Elementary school
Grade 1 3,138 16.4±0.0 - 12.8 13.4 13.6 14.1 14.4 14.9 16.0 17.6 18.6 19.5 20.9 22.0 23.7
Grade 2 3,180 16.9±0.1 0.5 12.9 13.4 13.7 14.2 14.5 15.1 16.3 18.1 19.5 20.5 21.9 22.9 25.1
Grade 3 3,149 17.5±0.1 0.6 13.2 13.7 14.0 14.5 14.8 15.4 17.0 19.1 20.3 21.3 23.0 23.8 25.8
Grade 4 3,201 18.1±0.1 0.6 13.1 13.7 14.1 14.7 15.1 15.8 17.6 20.0 21.5 22.7 24.1 25.2 27.6
Grade 5 3,180 18.9±0.1 0.8 13.5 14.2 14.6 15.2 15.7 16.4 18.3 20.8 22.4 23.6 25.2 26.3 28.6
Grade 6 3,132 19.7±0.1 0.8 14.0 14.7 15.2 15.8 16.4 17.2 19.2 21.7 23.3 24.3 26.2 27.6 29.9
Middle school
Grade 1 4,785 20.4±0.1 0.7 14.5 15.3 15.7 16.5 17.1 18.0 19.9 22.3 24.0 25.4 27.5 28.9 31.5
Grade 2 4,900 21.0±0.1 0.6 15.2 15.9 16.4 17.2 17.8 18.6 20.4 22.8 24.6 25.9 28.3 29.6 32.7
Grade 3 5,010 21.5±0.1 0.5 15.7 16.5 16.9 17.6 18.2 19.0 20.8 23.3 24.9 26.3 28.4 30.0 33.4
High school
Grade 1 5,839 21.9±0.1 0.4 16.0 16.8 17.2 18.0 18.5 19.3 21.2 23.5 25.2 26.6 29.0 30.6 33.4
Grade 2 6,496 22.0±0.1 0.1 16.1 17.0 17.5 18.1 18.6 19.5 21.3 23.7 25.4 27.0 29.4 30.8 34.2
Grade 3 6,905 22.2±0.1 0.2 16.2 17.1 17.5 18.3 18.8 19.6 21.6 24.1 25.8 27.2 29.6 31.4 34.7

SE, standard error.

*

Difference values are the mean differences in body mass index between the corresponding grade-students and the 1-year younger grade-students.

Table 5.

Comparison of mean height and weight by sex and school grade between Korea School Health Examination Survey (KSHES) 2010 (n=188,352) and 2018 (n=107,954)

School grade KSHES 2010
KSHES 2018
Difference P-value KSHES 2010
KSHES 2018
Difference P-value
No. Height (cm) No. Height (cm) No. Weight (kg) No. Weight (kg)
Boys
Elementary school
Grade 1 7,487 121.8±0.1 3,299 122.1±0.1 0.3 0.0694 7,488 24.9±0.1 3,299 25.2±0.1 0.3 0.0694
Grade 2 7,476 127.7±0.1 3,357 127.8±0.1 0.1 0.5393 7,475 28.4±0.1 3,357 28.9±0.2 0.5 0.0125
Grade 3 7,578 133.1±0.1 3,383 133.8±0.1 0.7 <0.0001 7,576 32.1±0.1 3,383 33.3±0.2 1.2 <0.0001
Grade 4 7,618 138.4±0.1 3,355 139.7±0.1 1.3 <0.0001 7,617 35.9±0.1 3,355 37.9±0.2 2.0 <0.0001
Grade 5 7,598 144.0±0.1 3,384 145.0±0.1 1.0 <0.0001 7,594 41.1±0.1 3,384 42.7±0.2 1.6 <0.0001
Grade 6 7,669 150.2±0.1 3,333 152.2±0.1 2.0 <0.0001 7,669 46.1±0.1 3,333 49.1±0.3 3.0 <0.0001
Middle school
Grade 1 9,389 157.9±0.1 5,038 160.4±0.1 2.5 <0.0001 9,388 51.7±0.2 5,038 54.6±0.2 2.9 <0.0001
Grade 2 9,294 164.2±0.1 5,102 166.3±0.1 2.1 <0.0001 9,290 57.2±0.2 5,102 60.7±0.3 3.5 <0.0001
Grade 3 9,107 168.9±0.1 5,315 170.2±0.1 1.3 <0.0001 9,106 61.5±0.2 5,315 64.6±0.2 3.1 <0.0001
High school
Grade 1 9,220 171.8±0.1 6,188 172.6±0.1 0.8 <0.0001 9,219 64.7±0.2 6,188 67.8±0.2 3.1 <0.0001
Grade 2 8,952 173.0±0.1 6,448 173.3±0.1 0.3 0.0383 8,952 66.6±0.2 6,448 69.3±0.2 2.7 <0.0001
Grade 3 8,884 173.7±0.1 6,837 173.8±0.1 0.1 0.4868 8,884 68.1±0.2 6,837 71.3±0.2 3.2 <0.0001

Girls
Elementary school
Grade 1 6,955 120.6±0.1 3,138 120.9±0.1 0.3 0.0652 6,955 23.7±0.1 3,138 24.2±0.1 0.5 0.0021
Grade 2 6,810 126.4±0.1 3,180 126.8±0.1 0.4 0.0136 6,809 26.9±0.1 3,180 27.4±0.1 0.5 0.0020
Grade 3 7,025 132.0±0.1 3,149 132.4±0.1 0.4 0.0147 7,024 30.3±0.1 3,149 30.8±0.1 0.5 0.0023
Grade 4 7,162 138.1±0.1 3,201 139.1±0.1 1.0 <0.0001 7,161 34.2±0.1 3,201 35.3±0.2 1.1 <0.0001
Grade 5 7,024 144.6±0.1 3,180 145.6±0.1 1.0 <0.0001 7,023 39.2±0.1 3,180 40.3±0.2 1.1 <0.0001
Grade 6 7,026 151.2±0.1 3,132 152.2±0.1 1.0 <0.0001 7,024 44.4±0.1 3,132 46.0±0.3 1.6 <0.0001
Middle school
Grade 1 7,839 155.5±0.1 4,785 156.9±0.1 1.4 <0.0001 7,838 48.2±0.2 4,785 50.4±0.2 2.2 <0.0001
Grade 2 7,501 158.2±0.1 4,900 158.9±0.1 0.7 <0.0001 7,500 51.5±0.2 4,900 53.2±0.2 1.7 0.0332
Grade 3 7,496 159.6±0.1 5,010 160.3±0.1 0.7 <0.0001 7,496 53.2±0.1 5,010 55.4±0.2 2.2 <0.0001
High school
Grade 1 7,395 160.6±0.1 5,839 160.9±0.1 0.3 0.0361 7,395 54.9±0.2 5,839 56.7±0.2 1.8 <0.0001
Grade 2 7,094 160.7±0.1 6,496 160.9±0.1 0.2 0.1585 7,093 55.5±0.2 6,496 57.0±0.2 1.5 <0.0001
Grade 3 7,217 160.9±0.1 6,905 160.9±0.1 0.0 1.0000 7,217 55.6±0.2 6,905 57.5±0.2 1.9 <0.0001

Values are presented as mean±standard error.