Table 1Distribution of sociodemographic characteristic of participants by sex.
Variable |
Category |
Males (n = 942) n (%) |
Females (n = 710) n (%) |
Total (n = 1,652) n (%) |
p
|
Sociodemographic characteristics |
|
|
|
|
Father's age (y) |
46 under |
368 (39.1) |
278 (39.2) |
646 (39.1) |
NS |
47–49 |
342 (36.3) |
263 (37.0) |
605 (36.6) |
50 and older |
232 (24.6) |
169 (23.8) |
401 (24.3) |
Mean ± SD∗
|
47.8 ± 3.8 |
47.5 ± 3.7 |
47.7 ± 3.7 |
NS |
Father's education |
≤ Elementary |
62 (6.6) |
42 (5.9) |
104 (6.3) |
NS |
Junior high school |
116 (12.3) |
88 (12.4) |
204 (12.3) |
High school |
453 (48.1) |
386 (54.4) |
839 (50.8) |
College or higher |
311 (33.0) |
194 (27.3) |
505 (30.6) |
Mother's age |
Under 43 |
362 (38.4) |
276 (38.9) |
638 (38.6) |
NS |
44–45 |
272 (28.9) |
208 (29.3) |
480 (29.1) |
45 and older |
308 (32.7) |
226 (31.8) |
534 (32.3) |
Mean ± SD∗
|
44.7 ± 3.7 |
44.4 ± 3.4 |
44.5 ± 3.5 |
NS |
Mother's education |
≤ Elementary |
81 (8.6) |
52 (7.3) |
133 (8.1) |
NS |
Junior high school |
169 (17.9) |
137 (19.3) |
306 (18.5) |
High school |
555 (58.9) |
433 (61.0) |
988 (59.8) |
College or higher |
137 (14.5) |
88 (12.4) |
225 (13.6) |
Family monthly income, Korean (US$) |
≤ 240 |
298 (31.6) |
256 (36.1) |
554 (33.5) |
NS |
241–350 |
346 (36.7) |
242 (34.1) |
588 (35.6) |
350≤ |
298 (31.6) |
212 (29.9) |
510 (30.9) |
Mean ± SD∗
|
331.2 ± 192.8 |
324.3 ± 200.5 |
328.2 ± 196.1 |
NS |
Frequency of having breakfast |
Every day |
598 (63.5) |
418 (58.9) |
1,016 (61.5) |
|
Sometimes/Never |
344 (36.6) |
292 (41.1) |
636 (38.5) |
NS |
BMI†
|
Normal |
798 (84.7) |
667 (93.9) |
1,465 (88.7) |
0.001 |
Overweight |
144 (15.3) |
43 (6.1) |
187 (11.3) |
Mean ± SD∗
|
22.3 ± 3.6 |
21.0 ± 2.8 |
21.8 ± 3.3 |
0.001 |
Subjects |
Score level |
|
|
|
|
Language |
T1 |
282 (29.9) |
248 (34.9) |
530 (32.1) |
0.027 |
T2 |
322 (34.2) |
248 (34.9) |
570 (34.5) |
T3 |
338 (35.9) |
214 (30.1) |
552 (33.4) |
Mean ± SD∗
|
94.0 ± 20.8 |
97.5 ± 19.1 |
95.5 ± 20.2 |
0.000 |
Mathematics |
T1 |
321 (34.1) |
228 (32.1) |
549 (33.2) |
0.011 |
T2 |
277 (29.4) |
257 (36.2) |
534 (32.3) |
T3 |
344 (36.5) |
225 (31.7) |
569 (34.4) |
Mean ± SD∗
|
94.7 ± 18.5 |
95.1 ± 17.1 |
94.9 ± 17.9 |
NS |
Foreign Language |
T1 |
288 (30.6) |
247 (34.8) |
535 (32.4) |
0.01 |
T2 |
300 (31.8) |
247 (34.8) |
547 (33.1) |
T3 |
354 (37.6) |
216 (30.4) |
570 (34.5) |
Mean ± SD∗
|
93.9 ± 20.4 |
96.6 ± 18.8 |
95.1 ± 19.7 |
0.006 |
Mean score of 3 individuals |
T1 |
302 (32.1) |
249 (35.1) |
551 (33.4) |
NS |
T2 |
310 (32.9) |
247 (34.8) |
557 (33.7) |
T3 |
330 (35.0) |
214 (30.1) |
544 (32.9) |
Mean ± SD∗
|
94.2 ± 17.8 |
96.4 ± 16.1 |
95.1 ± 17.1 |
0.009 |
Table 2Mean differences of language, mathematics, foreign language, and mean scores by skipping breakfast and overweight by sex.
Variables |
Males
|
Females
|
Eaters |
Skippers |
Difference |
Eaters |
Skippers |
Difference |
Language |
96.4 |
89.7 |
6.7∗
|
101.1 |
92.4 |
8.6∗
|
Mathematics |
96.9 |
91.0 |
5.7∗
|
98.2 |
90.7 |
7.5∗
|
Foreign language |
96.3 |
89.7 |
6.6∗
|
100.4 |
91.2 |
9.2∗
|
Mean scores |
96.5
|
90.1
|
6.4∗
|
99.9
|
91.4
|
8.5∗
|
|
Normal
|
Overweight
|
Difference
|
Normal
|
Overweight
|
Difference
|
Language |
94.0 |
93.5 |
0.5 |
97.5 |
98.3 |
0.8 |
Mathematics |
94.7 |
95.1 |
−0.4 |
95.2 |
93.3 |
1.9 |
Foreign language |
93.7 |
93.6 |
0.1 |
96.7 |
94.6 |
2.1 |
Mean scores |
94.0 |
94.2 |
−0.2 |
96.5 |
95.4 |
1.1 |
Table 3Odds ratios based on multivariate logistic regression models for higher academic achievement (language, mathematics, foreign language, mean scores).
Correlate |
Highest score (vs. lowest score) odds ratio (95% confidence intervals)
|
Categories |
Males
|
Females
|
Mean scores (n = 1,095) |
Language (n = 620) |
Mathematics (n = 665) |
Foreign language (n = 642) |
Language (n = 462) |
Mathematics (n = 463) |
Foreign language (n = 463) |
BMIa
|
Normal |
Reference |
|
|
Reference |
|
|
Reference |
Overweight |
0.52 (0.29–0.94)* |
1.05 (0.60–1.82) |
0.61 (0.30–1.16) |
1.80 (0.55–5.91) |
0.68 (0.26–1.78) |
0.96 (0.35–2.65) |
0.46 (0.27–0.79)** |
Breakfast |
Every day |
Reference |
|
|
Reference |
|
|
Reference |
Sometimes |
0.70 (0.42–1.15) |
0.68 (0.42–1.10) |
0.90 (0.54–1.49) |
0.55 (0.32–0.94)* |
0.41 (0.24–0.68)*** |
0.43 (0.24–0.74)** |
0.55 (0.38–0.81)** |
Never |
0.46 (0.23–0.91)* |
0.67 (0.34–1.31) |
0.59 (0.29–1.21) |
0.41 (0.19–0.88)* |
0.24 (0.11–0.53)*** |
0.18 (0.08–0.44)*** |
0.40 (0.24–0.67)** |