Table 2 Characteristics of females by time intervals (n = 1,157,958)
1977–1980 (n = 58,181) | 1981–1985 (n = 90,198) | 1986–1990 (n = 1,09,192) | 1991–1995 (n = 1,43,745) | 1996–2000 (n = 1,50,368) | 2001–2005 (n = 1,53,276) | 2006–2010 (n = 1,45,457) | 2011–2015 (n = 1,53,623) | 2016–2020 (n = 1,53,908) | Total (n = 11,57,958) | P value for trend | |
|---|---|---|---|---|---|---|---|---|---|---|---|
Age (mean ± SD) | 17.5 ± 0.4 | 17.4 ± 0.4 | 17.4 ± 0.3 | 17.3 ± 0.3 | 17.3 ± 0.4 | 17.2 ± 0.4 | 17.1 ± 0.4 | 17 ± 0.6 | 17.0 ± 0.5 | 17.2 ± 2.7 | 0.48 |
Height (cm ± SD) | 161.9 ± 5.9 | 162.1 ± 5.9 | 162.5 ± 6.0 | 162.1 ± 6.2 | 162.0 ± 6.2 | 162.1 ± 6.3 | 161.8 ± 6.2 | 162.2 ± 6.3 | 162.2 ± 6.2 | 162.2 ± 6.2 | 0.51 |
BMI (mean ± SD) | 21.0 ± 2.9 | 20.9 ± 3.0 | 21.1 ± 3.2 | 21.1 ± 3.4 | 21.2 ± 3.5 | 21.2 ± 3.7 | 21.5 ± 3.9 | 22 ± 4.2 | 22.6 ± 4.3 | 21.5 ± 3.7 | 0.002 |
CDC BMI groups (% of each BMI percentile category) | 0.001 | ||||||||||
Underweight | 2229 (3.8) | 3927 (4.4) | 4581 (4.2) | 6741 (4.7) | 7127 (4.7) | 7502 (4.9) | 7045 (4.9) | 6213 (4.1) | 5806 (3.8) | 51,171 (4.4) | |
Normal weight | 50,633 (87.3) | 77,811 (86.5) | 92,536 (84.9) | 1,19,379 (83.1) | 1,23,537 (82.3) | 1,23,963 (81.1) | 1,14,648 (79.0) | 1,17,181 (76.8) | 1,14,940 (75.2) | 9,34,628 (81.0) | |
Overweight | 4438 (7.7) | 6917 (7.7) | 9590 (8.8) | 13,536 (9.4) | 14,506 (9.7) | 15,387 (10.1) | 16,294 (11.2) | 19,879 (13.0) | 21,142 (13.8) | 1,21,689 (10.5) | |
Obese | 704 (1.2) | 1249 (1.4) | 2327 (2.1) | 3934 (2.7) | 4891 (3.3) | 6051 (4.0) | 7049 (4.9) | 9377 (6.1) | 10,918 (7.1) | 46,500 (4.0) | |
Immigrants (% of time interval) | 8548 (14.7) | 8206 (9.1) | 7327 (6.7) | 16,307 (11.3) | 27,728 (18.4) | 33,836 (221) | 26,814 (18.4) | 18,207 (11.9) | 14,063 (9.1) | 1,61,036 (13.9) | 0.61 |
Years of education ≥ 11 (% of time interval) | 48,412 (85.3) | 80,902 (91.0) | 1,04,099 (96.6) | 1,39,508 (97.6) | 1,45,783 (97.0) | 1,49,065 (97.3) | 1,42,693 (98.1) | 1,50,279 (98.1) | 1,33,567 (97.8) | 1,094,308 (96.4) | 0.02 |
Socioeconomic status (% of each category) | 0.19 | ||||||||||
Low | 11,500 (20.7) | 19,582 (22.2) | 21,518 (20.1) | 28,739 (20.2) | 33,465 (22.3) | 33,790 (22.1) | 32,358 (22.3) | 32,031 (20.9) | 31,633 (20.7) | 2,44,616 (21.3) | |
Medium | 28,350 (51.1) | 45,566 (51.6) | 58,008 (54.1) | 78,144 (55.0) | 82,946 (55.3) | 85,663 (56.0) | 79,580 (54.8) | 83,523 (54.6) | 83,251 (54.4) | 6,25,031 (54.5) | |
High | 15,622 (28.2) | 23,099 (26.2) | 27,757 (25.9) | 35,140 (24.7) | 33,483 (22.3) | 33,524 (21.9) | 33,350 (23.0) | 37,504 (24.5) | 38,052 (24.9) | 2,77,531 (24.2) | |