Table 1 Characteristics of the study participants (N = 39,315)
Mean | SD | |
Age (fathers’ age) | 32.9 | 5.7 |
Educational level | n | % |
Junior high school | 1969 | 5.0 |
High school | 14,018 | 35.7 |
Higher professional school | 822 | 2.1 |
Professional school | 7629 | 19.4 |
Junior college | 846 | 2.2 |
University | 11,993 | 30.5 |
Graduate school | 2038 | 5.2 |
Household income | ||
< 2 million yen | 1657 | 4.2 |
2.0–3.9 million yen | 13,223 | 33.6 |
4.0–5.9 million yen | 13,416 | 34.1 |
6.0–7.9 million yen | 6572 | 16.7 |
8.0–9.9 million yen | 2746 | 7.0 |
10–11.9 million yen, | 1001 | 2.6 |
12–14.9 million yen | 382 | 1.0 |
15–19.9 million yen | 216 | 0.6 |
≥ 20 million yen | 102 | 0.3 |
Breakfast eating | ||
Everyday | 20,770 | 52.8 |
Not everyday | 18,545 | 47.2 |
Eating outside | ||
≦ 3 times/month | 16,789 | 42.7 |
≧ once/week | 22,526 | 57.3 |
Instant food eating | ||
≦ 3 times/month | 20,555 | 52.3 |
≧ once /week | 18,760 | 47.7 |
Eating over | ||
No | 11,341 | 28.9 |
Yes | 27,974 | 71.2 |
Eating fast | ||
Normal to too slow | 12,859 | 32.7 |
Too fast to slightly fast | 26,456 | 67.3 |
Partners’ age (mothers’ age) | 31.1 | 4.9 |
n | % | |
Partners’ educational level (mothers’ education) | ||
Junior high school | 1411 | 3.6 |
High school | 11,557 | 29.4 |
Higher professional school | 644 | 1.6 |
Professional school | 9207 | 23.4 |
Junior college | 7080 | 18.0 |
University | 8768 | 22.3 |
Graduate school | 648 | 1.7 |
Partners’ occupation (mothers’ occupation) | ||
Administrative and managerial workers | 224 | 0.6 |
Professional and engineering workers | 9637 | 24.5 |
Clerical workers | 6889 | 17.5 |
Sales workers | 2139 | 5.4 |
Service workers | 5658 | 14.4 |
Security workers | 116 | 0.3 |
Agricultural, forestry, and fishery workers | 160 | 0.4 |
Manufacturing process workers | 1356 | 3.5 |
Transport and machine operation workers | 76 | 0.2 |
Construction and mining workers | 30 | 0.1 |
Carrying, cleaning packaging, and related workers | 163 | 0.4 |
Full-time homemaker | 10,922 | 27.8 |
Student, graduate student | 155 | 0.4 |
Unemployed | 1214 | 3.1 |
Workers not otherwise classifiable | 576 | 1.5 |