Table 1 Descriptive statistics of the study sample
Variable | Definition | 2004 | 2006 | ||
|---|---|---|---|---|---|
Mean | Std. Dev. | Mean | Std. Dev. | ||
Outcome variables | |||||
Kilocalorie | Average daily calorie intake (in kilocalories) | 1,909.53 | 608.63 | 1,958.93 | 627.33 |
Carbohydrate | Average daily carbohydrate intake (in grams) | 255.70 | 95.81 | 268.68 | 92.46 |
Protein | Average daily protein intake (in grams) | 62.80 | 24.74 | 63.87 | 23.45 |
Fat | Average daily fat intake (in grams) | 70.52 | 32.33 | 70.31 | 36.01 |
Independent variables | |||||
Age | Calculated age in years | 11.43 | 2.73 | 13.40 | 2.72 |
Household income per capita | Per capita household income (in thousand RMB at 2006) | 6.55 | 6.01 | 7.13 | 6.68 |
Supermarket density | Number of supermarkets within 5 km of neighborhood | 6.59 | 5.87 | 3.08 | 3.25 |
Wet market density | Number of wet markets within 5 km of neighborhood | 6.25 | 7.88 | 4.17 | 4.57 |
Fast food restaurant density | Number of fast food restaurants (e.g. McDonald’s, KFC) in neighborhood | 1.02 | 2.68 | 0.45 | 2.35 |
Owning car | Household automobile ownership (own = 1, not own = 0) | 0.04 | 0.19 | 0.07 | 0.26 |
Bus stop | Existence of bus stop(s) in neighborhood (yes = 1, no = 0) | 0.70 | 0.46 | 0.77 | 0.42 |
Female | Female = 1, male = 0 | 0.51 | 0.50 | 0.51 | 0.50 |
Maternal education | Mother’s education in years | 10.84 | 2.87 | 10.84 | 2.87 |
Child dummy | 1 if aged 6–12, 0 if aged 13–17 | 0.66 | 0.48 | 0.45 | 0.50 |