The Effect of Obesity on
Children’s Educational
Attainment: 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 increase in
Korea.
<Proportion of obese students according to IBW>
Year
Obese
2006
2008
11.62%
11.24%
2010
14.25%
• In response to this problem, special act on
Children’s food safety management was
enacted in 2009.
Background
• An amendment to Special Act on Children’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 children’s
academic achievement?
Literature Review
• Datar & Sturm(2006)
– Moving from non-overweight to overweight between
Kindergarten entry and end of third grade was significantly
associated with reductions in test scores, teacher ratings of
social-behavioral outcomes and approaches to learning
among female 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
Development Institute, 2011) were used for
this study.
– Data were collected by questionnaires from
parents, students, teachers, and school
administrators. (Students’ weight and height
were asked for the first time.)
– About 12,000 6th grade students, enrolled in
elementary schools, were sampled.
Data & Methodology
• The body mass index(BMI) is calculated
according to Korean standard.
<Cut-off points for BMI: Republic of Korea>
Gender
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 were set by Center for Disease Control and Korean Pediatric Society.
Relative Weight Status: Gender &
Geographical Region
BMI category
Male
N
Underweight
Female
%
N
Chisquared
Total
%
N
%
263
4.2
308
5.5
571
4.8
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
6,195
100
5,631
100
11,826
100
Normal
Total
BMI category
Seoul
N
Underweight
Normal
Metro area Middle town Small town
%
58
N
%
N
%
N
%
234
4.5
5.0
94
4.7
185
5.2
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
1,154
100
1,985
100
3,525
100
5,162
100
Total
*: p<0.05, **: p<0.01, ***: p<0.001
36.60**
Chisquared
26.41**
Relative Weight Status: Parental Education
BMI category
Underweight
Father’s
education
Normal
High
school
N
%
N
%
N
%
3.9
181
4.3
239
5.4
3,277 77.2
3,583
8.7
13
261 78.9
Undergraduate
Graduate or
higher
N
44
5.7
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
Underweight
High
school
N
%
N
%
N
%
5.9
211
3.9
237
5.9
4,215 78.3
3,245
8.1
19
Undergraduate
Graduate or
higher
N
Chisquared
%
12
3.8
Normal
243 75.0
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
*: p<0.05, **: p<0.01, ***: p<0.001
58.42**
628 82.0
28
Middle
school
Chisquared
%
Overweight
BMI category
Mother’s
education
Middle
school
268 84.0
53.08**
Relative Weight Status: Self-esteem & Depression
<Self-esteem>
BMI
category
Underweight
Number of
Students
Mean
Standard
Deviation
Standard
Error
556
3.55
0.66
0.03
Normal
9,235
3.58
0.65
0.01
Overweight
1,164
3.46
0.62
0.02
721
3.40
0.63
0.02
11,676
3.56
0.65
0.01
Obesity
Total
F-statistic
(Post-Hoc)
26.444***
<Depression>
BMI
category
Underweight
Number of
Students
Mean
Standard
Deviation
Standard
Error
554
2.15
1.17
0.05
Normal
9,205
2.12
1.12
0.01
Overweight
1,163
2.23
1.14
0.03
721
2.25
1.14
0.04
11,643
2.14
1.12
0.01
Obesity
Total
*: p<0.05, **: p<0.01, ***: p<0.001
F-statistic
(Post-Hoc)
6.476***
Relative Weight Status: Bullying
BMI
category
Underweight
Number of
Students
Mean
Standard
Deviation
Standard
Error
555
2.02
1.27
0.05
Normal
9,193
1.96
1.21
0.01
Overweight
1,163
2.13
1.27
0.04
720
2.23
1.30
0.05
11,631
2.00
1.23
0.01
Obesity
Total
*: p<0.05, **: p<0.01, ***: p<0.001
F-statistic
(Post-Hoc)
15.728***
HLM results for Reading, Math,
Science Scores
BMI
category
Reading
Coefficient
…
Math
Science
Standard Coefficient Standard Coefficient
error
error
…
…
Overweight
-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
…
…
…
…
…
Standard
error
…
…
…
HLM results controlling for gender
interaction terms
BMI
category
Reading
Coefficient
…
…
Math
Science
Standard Coefficient Standard Coefficient
error
error
Standard
error
…
…
…
…
…
Overweight
1.223
0.819
1.192#
0.704
1.545#
0.812
Female ×
Overweight
-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
better 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 controlled.