The Effect of Obesity on Chil-dren’s Educational Attain-

ment: The Korean Case

Kwanghyun Lee(Busan National University of Education)

Yongjae Kwon(Kookmin University)

Road Map

• Background & Motivation of Research• Literature Review• Data and Methodology• Empirical Results• Summary and Conclusion

Background

• Obesity among children is on the in-crease in Korea.

• In response to this problem, special act on Children’s food safety management was enacted in 2009.

Year Obese

2006 11.62%

2008 11.24%

2010 14.25%

<Proportion of obese students according to IBW>

Background

• An amendment to Special Act on Chil-dren’s Food Safety Management (effective from January 1st 2010)– Setting standards for nutritional contents of

high calorie and poor-nutritive foods (Article 3)

1 Regulation of concrete permissible limits on calorie and nutritive value for high calorie and poor-nutritive foods are required.

2 Classify the nutritional contents of children’s favorite foods into snacks and meal substitutes, and set the standards for the levels of calories, saturated fats, sugars, sodium and protein.

3 Specify the list of foods that are subject to prohibition of sale at school and advertising restrictions in expectation of preventing children’s obesity and creating a healthy eating environment.

Source: Korea Food and Drug Administration

Motivation of Research

• Despite the urgency of the matter, research measuring the effects of obesity on students’ lives and their academic achievement were rare in South Korea.

Research Question

• How are the relative weight statuses of children related to variables such as gender, geographic region, parental education, eating habit, and physical activity?

• Are the differences above statistically significant?

• Does the relative weight statuses have significant relationship with chil-dren’s academic achievement?

Literature Review• Datar & Sturm(2006)

– Moving from non-overweight to overweight between Kinder-garten entry and end of third grade was significantly associ-ated with reductions in test scores, teacher ratings of social-behavioral outcomes and approaches to learning among fe-male students.

• Sabia(2007)– Significant negative relationship between BMI and GPA was

found in white female aged 14-17 while the relationship was not convincing enough in nonwhite males and females.

• Kaestner & Grossman(2009)– Children who are overweight or obese have achievement

scores that are about the same as children with average weight.

Data & Methodology

• Dataset from ‘analysis on the actual status and the level of Korean schools: A study on elementary schools’ (Korea Education Devel-opment Institute, 2011) were used for this study. – Data were collected by questionnaires from par-

ents, students, teachers, and school administra-tors. (Students’ weight and height were asked for the first time.)

– About 12,000 6th grade students, enrolled in ele-mentary schools, were sampled.

Data & Methodology

• The body mass index(BMI) is calcu-lated according to Korean standard.

Gen-der

Underweight Normal Overweight Obese

Male <14.93 ≥14.93 and <22.57

≥22.57 and <25.00

≥25.00

Female <14.73 ≥14.73 and <21.51

≥21.51 and <23.99

≥23.99

<Cut-off points for BMI: Republic of Ko-rea>

* Cut-off points were set by Center for Disease Control and Korean Pediatric Society.

Relative Weight Status: Gender & Ge-ographical Region

BMI cate-gory

Male Female Total Chi-squaredN % N % N %

Underweight 263 4.2 308 5.5 571 4.8 36.60**

Normal 4,831 78.0 4,512 8.1 9,343 79.0

Overweight 654 1.6 523 9.3 1,177 10.0

Obesity 447 7.2 288 5.1 735 6.2

Total 6,195 100 5,631 100 11,826 100BMI cate-

gorySeoul Metro

areaMiddle town

Small town

Chi-square

dN % N % N % N %

Underweight 58 5.0 94 4.7 185 5.2 234 4.5 26.41**

Normal 911 78.9

1,589

8.1 2,830 8.3 4,013

77.7

Overweight 119 1.3 188 9.5 333 9.4 537 1.4

Obesity 66 5.7 114 5.7 177 5.0 378 7.3

Total 1,154

100 1,985

100 3,525 100 5,162

100

*: p<0.05, **: p<0.01, ***: p<0.001

Relative Weight Status: Parental EducationBMI category Middle

schoolHigh

schoolUnder-

graduateGraduate or higher

Chi-square

dN % N % N % N %

Underweight 13 3.9 181 4.3 239 5.4 44 5.7 58.42**

Normal 261 78.9

3,277

77.2

3,583 8.7 628 82.0

Overweight 28 8.5 475 11.2

402 9.1 66 8.6

Obesity 29 8.8 313 7.4 215 4.8 28 3.7

Total 331 100 4,246

100 4,439 100 766 100

BMI category Middle school

High school

Under-graduate

Graduate or higher

Chi-square

dN % N % N % N %

Underweight 19 5.9 211 3.9 237 5.9 12 3.8 53.08**

Normal 243 75.0

4,215

78.3

3,245 8.1 268 84.0

Overweight 37 11.4

585 1.9 373 9.2 30 9.4

Obesity 25 7.7 370 6.9 194 4.8 9 2.8

Total 324 100 5,381

100 4,049 100 319 100

Father’s educa-tion

Mother’s educa-tion

*: p<0.05, **: p<0.01, ***: p<0.001

Relative Weight Status: Self-esteem & De-pression

BMI cate-gory

Number of Stu-dents

Mean Stan-dard

Devia-tion

Standard Error

F-statis-tic (Post-

Hoc)

Under-weight

556 3.55 0.66 0.03 26.444***

Normal 9,235 3.58 0.65 0.01

Overweight 1,164 3.46 0.62 0.02

Obesity 721 3.40 0.63 0.02

Total 11,676 3.56 0.65 0.01BMI cate-gory

Number of Stu-dents

Mean Stan-dard

Devia-tion

Standard Error

F-statis-tic (Post-

Hoc)

Under-weight

554 2.15 1.17 0.05 6.476***

Normal 9,205 2.12 1.12 0.01

Overweight 1,163 2.23 1.14 0.03

Obesity 721 2.25 1.14 0.04

Total 11,643 2.14 1.12 0.01

<Self-esteem>

<Depression>

*: p<0.05, **: p<0.01, ***: p<0.001

Relative Weight Status: Bullying

BMI cate-gory

Number of Stu-dents

Mean Stan-dard

Devia-tion

Standard Error

F-statis-tic (Post-

Hoc)

Under-weight

555 2.02 1.27 0.05 15.728***

Normal 9,193 1.96 1.21 0.01

Overweight 1,163 2.13 1.27 0.04

Obesity 720 2.23 1.30 0.05

Total 11,631 2.00 1.23 0.01

*: p<0.05, **: p<0.01, ***: p<0.001

HLM results for Reading, Math, Sci-ence Scores

BMI cat-egory

Reading Math Science

Coeffi-cient

Stan-dard er-

ror

Coeffi-cient

Stan-dard er-

ror

Coeffi-cient

Standard error

… … … … … … …

Over-weight

-0.245 0.539 0.261 0.509 0.254 0.529

Obesity -1.513* 0.701 -1.182* 0.574 -1.288# 0.698

… … … … … … …

#: p<0.10, *: p<0.05, **: p<0.01, ***: p<0.001

HLM results controlling for gender interaction terms

BMI cat-egory

Reading Math Science

Coeffi-cient

Stan-dard er-

ror

Coeffi-cient

Stan-dard er-

ror

Coeffi-cient

Standard error

… … … … … … …

Over-weight

1.223 0.819 1.192# 0.704 1.545# 0.812

Female × Over-weight

-3.134** 1.195 -2.002* 0.982 -2.780* 1.095

Obesity -0.791 0.859 -1.383# 0.782 -1.642 0.947

Female × Obesity

-1.726 1.342 0.543 1.166 0.939 1.395

… … … … … … …#: p<0.10, *: p<0.05, **: p<0.01, ***: p<0.001

Summary and Conclusion• Obese female and male students tended to show

lower academic achievement.

• In case of male, overweight students showed bet-ter academic performance compared to normal and obese students. However, this tendency did not appear in female students.

• HLM results demonstrated that obese students showed significantly lower academic performance compared to other students after explanatory variables such as family background, psychological variables, and school/teacher variables were con-trolled.