TABLE 2.
Subject characteristics in 2006 and 2-y change values1
| Girls (n = 4604) | Boys (n = 3668) | |
| Characteristics | ||
| Age (y) | 15.7 ± 1.9 (15.8)2 | 15.6 ± 1.9 (15.6) |
| Non-Hispanic white (%)3 | 93.6 | 92.5 |
| Height (in) | 64.4 ± 2.9 (64) | 67.9 ± 4.4 (68) |
| ΔHeight (in) | 0.8 ± 1.4 (0.0) | 4.5 ± 2.7 (5.0) |
| BMI (kg/m2) | 21.4 ± 3.7 (20.8) | 21.7 ± 3.9 (21.0) |
| Obese (%)4 | 3.7 | 6.0 |
| Overweight or obese (%)4 | 16.3 | 23.5 |
| Physical activity (h/wk)5 | 9.7 ± 7.2 (8.3) | 11.8 ± 8.6 (10.0) |
| ΔPhysical activity (h/wk)5 | −0.62 ± 6.57 (−0.50) | −0.32 ± 7.8 (−0.31) |
| Census-tract median income (×$1000) | 70 ± 26 (66) | 71 ± 26 (67) |
| Frequency of family dinner ≥3 times/wk (%) | 79.7 | 84.8 |
| Dietary variables (servings/d) | ||
| Sugar-sweetened beverages | 0.79 ± 0.85 (0.57) | 1.29 ± 1.08 (1.07) |
| ΔSugar-sweetened beverages | −0.17 ± 0.80 (−0.07) | −0.13 ± 1.09 (−0.07) |
| Fast food | 0.42 ± 0.30 (0.34) | 0.64 ± 0.43 (0.55) |
| ΔFast food | −0.03 ± 0.30 (−0.01) | 0.03 ± 0.45 (0.01) |
| Sweets | 1.25 ± 0.99 (0.99) | 1.58 ± 1.27 (1.25) |
| ΔSweets | −0.14 ± 0.99 (−0.09) | −0.16 ± 1.24 (−0.13) |
| Salty snacks | 0.52 ± 0.44 (0.41) | 0.59 ± 0.50 (0.42) |
| ΔSalty snacks | −0.05 ± 0.46 (−0.01) | −0.04 ± 0.52 (0.00 |
| Total foods of low nutritional quality | 2.98 ± 1.80 (2.64) | 4.10 ± 2.31 (3.67) |
| ΔTotal foods of low nutritional quality | −0.40 ± 1.64 (−0.32) | −0.31 ± 2.14 (−0.28) |
| Fruit and vegetables | 3.07 ± 1.54 (2.76) | 2.89 ± 1.34 (2.68) |
| ΔFruit and vegetables | 0.11 ± 1.46 (0.08) | 0.06 ± 1.32 (0.01) |
| Screen time (h/d) | ||
| Television | 1.35 ± 1.07 (0.93) | 1.48 ± 1.12 (0.93) |
| ΔTelevision | −0.19 ± 1.01 (0.00) | −0.08 ± 1.12 (0.00) |
| Electronic games6 | 0.20 ± 0.39 (0.07) | 1.14 ± 1.15 (0.93) |
| ΔElectronic games6 | 0.01 ± 0.46 (0.00) | 0.07 ± 1.18 (0.00) |
| DVDs/videos | 0.72 ± 0.54 (0.93) | 0.74 ± 0.62 (0.93) |
| ΔDVDs/videos | 0.07 ± 0.63 (0.00) | 0.12 ± 0.74 (0.00) |
| Total screen time7 | 2.26 ± 1.43 (1.93) | 3.36 ± 2.13 (2.79) |
| ΔTotal screen time7 | −0.11 ± 1.43 (0.00) | 0.11 ± 2.14 (0.00) |
1
Values measured in 2008 minus values measured in 2006 (3200 girls and 2330 boys). DVD, digital versatile disc; Δ, change in or change in consumption of.
2
Mean ± SD; median in parentheses (all such values).
3
Calculation of the percentage did not include individuals with missing values in the denominator.
4
On the basis of cutoffs defined by the International Obesity Task Force.
5
Moderate-to-vigorous recreational physical activity (≥3 metabolic equivalents).
6
Video and computer games.
7
Did not include computer or Internet use for homework, work, or other recreational use (except for computer and Internet games, which were encompassed by electronic games).