Variables | Percent or mean ± SD | p valuea | ||
---|---|---|---|---|
All (n = 7530) | Boys (n = 3780) | Girls (n = 3750) | ||
Sociodemographic characteristics (1998) | ||||
 Age (years) | 6.2 ± 0.4 | 6.3 ± 0.3 | 6.2 ± 0.3 | 0.012 |
 Race/ethnicity |  |  |  | 0.153 |
  White | 58.0 | 58.5 | 57.5 |  |
  Black | 17.5 | 18.0 | 17.0 |  |
  Hispanic | 18.2 | 18.4 | 18.1 |  |
  Asian | 2.9 | 2.1 | 3.7 |  |
  Others | 3.4 | 3.0 | 3.7 |  |
 Parental education |  |  |  | 0.227 |
  ≤ High school | 33.8 | 35.5 | 32.1 |  |
  Vocational/college | 32.5 | 31.9 | 33.1 |  |
  Bachelor | 19.2 | 19.1 | 19.3 |  |
  ≥ Graduate | 14.5 | 13.5 | 15.5 |  |
 Household annual income ($) |  |  |  | 0.503 |
  ≤ 30,000 | 35.0 | 35.7 | 34.2 |  |
  > 30,000 but ≤ 50,000 | 24.1 | 24.4 | 23.8 |  |
  > 50,000 but ≤ 75,000 | 18.4 | 17.3 | 19.6 |  |
  > 75,000 | 22.5 | 22.6 | 22.4 |  |
 Urbanicity |  |  |  | 0.797 |
  Urban | 68.4 | 68.1 | 68.6 |  |
  Non-urban | 31.6 | 31.9 | 31.4 |  |
Weight statusb (1998) | ||||
 BMI (kg/m2) | 16.4 ± 2.2 | 16.4 ± 2.0 | 16.4 ± 2.3 | 0.684 |
 Overweight and obesity | 26.6 | 25.9 | 27.3 | 0.435 |
 Obesity | 11.3 | 11.6 | 10.9 | 0.590 |
Weight statusb (2007) | ||||
 BMI (kg/m2) | 22.9 ± 5.7 | 22.6 ± 5.2 | 23.2 ± 5.8 | 0.013 |
 Overweight and obesity | 35.5 | 35.6 | 35.4 | 0.903 |
 Obesity | 19.5 | 21.0 | 18.0 | 0.062 |