Table 1.
General characteristics of the sample according to sex-specific categories of dietary glycemic indexa
| Characteristics | Dietary glycemic index b | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Female adolescents | Male adolescents | |||||||||||||
| Low | Moderate | High | P value | Low | Moderate | High | P value | |||||||
| Mean | SD | Mean | SD | Mean | SD | Mean | SD | Mean | SD | Mean | SD | |||
| Dietary GI (units) | 46.8 | 0.3 | 51.0 | 0.1 | 56.6 | 0.4 | <0.001 | 47.6 | 0.3 | 51.9 | 0.1 | 57.0 | 0.3 | <0.001 |
| Age (years) | 15.5 | 0.2 | 16.2 | 0.3 | 16.0 | 0.2 | 0.123 | 15.4 | 0.2 | 16.0 | 0.2 | 15.6 | 0.2 | 0.185 |
| Socioeconomic status (%) | 0.549 | 0.117 | ||||||||||||
| Low | 30.0 | 25.6 | 30.9 | 27.7 | 32.6 | 31.2 | ||||||||
| Medium | 26.8 | 34.3 | 35.6 | 37.3 | 28.1 | 35.9 | ||||||||
| High | 43.3 | 40.1 | 33.5 | 35.0 | 39.3 | 32.9 | ||||||||
| Geographic region (%) | 0.186 | 0.515 | ||||||||||||
| North | 24.4 | 12.2 | 20.8 | 19.5 | 14.4 | 25.0 | ||||||||
| Central | 25.1 | 25.2 | 35.4 | 31.0 | 28.9 | 31.6 | ||||||||
| Metropolitan area | 24.5 | 30.3 | 15.4 | 14.3 | 19.8 | 12.0 | ||||||||
| South | 26.1 | 32.3 | 28.4 | 35.2 | 37.0 | 31.4 | ||||||||
| Weight status (%) | 0.379 | 0.001 | ||||||||||||
| Underweight | 1.3 | 1.0 | 1.9 | 1.2 | 0.9 | 0.7 | ||||||||
| Normal | 64.2 | 65.9 | 50.9 | 71.8 | 66.3 | 69.7 | ||||||||
| Overweight | 21.3 | 23.4 | 34.5 | 13.1 | 28.0 | 13.3 | ||||||||
| Obese | 13.3 | 9.7 | 12.7 | 13.9 | 4.9 | 16.3 | ||||||||
| Screen time (computer, TV, and video) (%) | 0.131 | 0.011 | ||||||||||||
| ≤ 2 h/day | 29.6 | 43.8 | 28.9 | 33.7 | 39.8 | 29.4 | ||||||||
| 2–4 h/day | 35.0 | 29.1 | 45.7 | 29.3 | 39.5 | 37.1 | ||||||||
| ≥ 4 h/day | 34.1 | 25.3 | 24.5 | 36.8 | 17.8 | 33.5 | ||||||||
| No data available | 13 | 1.7 | 1.0 | 0.3 | 2.9 | 0.0 | ||||||||
| Physical activity (%, age 12–14 years) | 0.174 | 0.034 | ||||||||||||
| Sedentary | 76.3 | 77.7 | 57.7 | 51.6 | 40.2 | 55.9 | ||||||||
| 1–2 activities | 18.9 | 20.0 | 36.4 | 44.9 | 50.5 | 41.1 | ||||||||
| ≥ 3 activities | 2.1 | 0.5 | 2.4 | 2.7 | 0.6 | 2.5 | ||||||||
| No data available | 2.7 | 1.8 | 3.4 | 0.7 | 8.6 | 0.5 | ||||||||
| Physical activity (%, age 15–19 years) | 0.239 | 0.131 | ||||||||||||
| Sedentary | 28.2 | 29.7 | 26.7 | 17.7 | 17.9 | 14.0 | ||||||||
| Moderately active | 6.1 | 22.2 | 16.7 | 9.4 | 19.8 | 19.4 | ||||||||
| Active | 65.8 | 46.0 | 56.7 | 72.9 | 62.3 | 66.6 | ||||||||
| No data available | 0.0 | 2.1 | 0.0 | 0.0 | 0.0 | 0.0 | ||||||||
| Dietary intake | ||||||||||||||
| Total energy intake (kcal/d) | 1795 | 53 | 1747 | 73 | 1828 | 58 | 0.707 | 2033 | 53 | 2121 | 61 | 2215 | 69 | 0.118 |
| Carbohydrate intake (g/d)c | 246.0 | 3.3 | 271.5 | 4.2 | 269.7 | 3.3 | <0.001 | 298.0 | 3.6 | 315.8 | 4.3 | 311.5 | 4.1 | 0.002 |
| Carbohydrate intake (% energy) | 54.9 | 0.7 | 61.5 | 1.2 | 60.8 | 0.8 | <0.001 | 55.8 | 0.7 | 59.5 | 0.8 | 59.1 | 0.7 | <0.001 |
| Protein intake (g/d)c | 58.5 | 1.0 | 52.7 | 1.2 | 51.9 | 0.8 | <0.001 | 67.9 | 1.1 | 63.8 | 1.0 | 60.5 | 1.2 | <0.001 |
| Protein intake (% energy) | 13.2 | 0.2 | 11.8 | 0.3 | 11.5 | 0.2 | <0.001 | 13.0 | 0.2 | 12.1 | 0.2 | 11.4 | 0.2 | <0.001 |
| Fat intake (g/d)c | 67.2 | 1.1 | 58.8 | 1.3 | 59.1 | 1.3 | <0.001 | 77.5 | 1.3 | 70.5 | 1.6 | 69.5 | 1.5 | <0.001 |
| Fat intake (% energy) | 33.9 | 0.5 | 28.8 | 0.9 | 29.4 | 0.7 | <0.001 | 33.2 | 0.5 | 29.8 | 0.7 | 29.6 | 0.5 | <0.001 |
| MUFA (g/d)c | 22.6 | 0.5 | 19.7 | 0.5 | 20.5 | 0.6 | <0.001 | 25.9 | 0.6 | 23.6 | 0.5 | 24.7 | 0.6 | 0.020 |
| PUFA (g/d)c | 14.3 | 0.4 | 14.1 | 0.4 | 14.5 | 0.4 | 0.750 | 17.4 | 0.4 | 17.5 | 0.7 | 16.8 | 0.4 | 0.424 |
| SFA (g/d)c | 25.8 | 0.5 | 22.1 | 0.6 | 22.7 | 0.7 | <0.001 | 29.4 | 0.7 | 26.2 | 0.7 | 26.5 | 0.7 | 0.002 |
| Trans fatty acids (g/d)c | 0.5 | 0.0 | 0.5 | 0.0 | 0.5 | 0.0 | 0.054 | 0.5 | 0.0 | 0.5 | 0.0 | 0.6 | 0.0 | 0.692 |
| Dietary fiber intake (g/d)c | 21.6 | 0.5 | 22.7 | 1.3 | 21.3 | 0.7 | 0.683 | 25.8 | 0.7 | 27.0 | 1.0 | 22.8 | 0.8 | 0.003 |
| Dietary sugar intake (g/d) | 94.1 | 4.9 | 109.9 | 7.2 | 112.3 | 4.4 | 0.021 | 108.4 | 4.1 | 116.2 | 6.4 | 134.6 | 4.4 | <0.001 |
| WC (cm) | 76.8 | 1.0 | 76.8 | 1.2 | 78.3 | 1.4 | 0.640 | 77.0 | 1.5 | 77.5 | 1.0 | 78.7 | 1.2 | 0.660 |
| Triglycerides (mg/dL) | 116.9 | 7.5 | 135.3 | 9.7 | 113.5 | 5.6 | 0.142 | 113.2 | 6.6 | 113.3 | 6.6 | 132.1 | 9.4 | 0.212 |
| HDL-c (mg/dL) | 45.1 | 0.8 | 48.7 | 2.0 | 43.0 | 1.4 | 0.075 | 43.3 | 0.9 | 41.3 | 0.9 | 43.0 | 0.8 | 0.231 |
| Systolic blood pressure (mmHg) | 107.1 | 0.9 | 108.9 | 1.1 | 110.0 | 1.2 | 0.169 | 111.2 | 1.5 | 110.9 | 1.0 | 113.3 | 1.0 | 0.219 |
| Diastolic blood pressure (mmHg) | 70.0 | 0.8 | 72.0 | 1.1 | 73.2 | 1.0 | 0.050 | 70.3 | 1.1 | 71.1 | 0.9 | 73.3 | 0.8 | 0.051 |
| Fasting serum glucose (mg/dL) | 80.4 | 1.0 | 79.0 | 1.2 | 77.6 | 1.0 | 0.172 | 81.3 | 0.8 | 80.2 | 1.3 | 81.5 | 1.4 | 0.733 |
| MetS prevalence (%)d | 9.5 | 9.7 | 16.9 | 0.234 | 6.9 | 3.8 | 8.4 | 0.344 | ||||||
Abbreviations: GI Glycemic index, GL glycemic load, kcal/d kilocalories per day, grams per day (g/d), MUFA monounsaturated fatty acids, PUFA polyunsaturated fatty acids, SFA saturated fatty acids, WC waist circumference, HDL-c high-density lipoprotein cholesterol, MetS metabolic syndrome
aValues are expressed as means and standard deviations (SD) for continuous variables, and data from categorical variables are shown as percentages
bCategories based on sex-specific tertiles of dietary GI. cValues were adjusted for energy intake using sex-specific residuals. dThe age-specific International Diabetes Foundation definition of the metabolic syndrome was used [36, 37]