Table 2.
Correlation of nutrients estimated by the first food frequency questionnaire (FFQ) and 7-day food diaries (FD).
| Nutrient | FD | FFQ | Difference (FFQ − FD) ± SD | FFQ:FD (%) | Spearman Coefficient (Unadjusted (r)) | Spearman Coefficient (Energy Adjusted (R)) | ||
|---|---|---|---|---|---|---|---|---|
| Mean | SD | Mean | SD | |||||
| Protein (g) | 62.154 | 18.59 | 81.68 | 34.59 | 19.52 ± 25.57 *** | 1.41 | 0.729 **** | 0.810 *** |
| Minerals (g) | 9.878 | 2.86 | 13 | 4.94 | 3.12 ± 3.574 *** | 1.30 | 0.685 **** | 0.617 **** |
| Fibre (g) | 11.439 | 3.8277 | 15.32 | 6.77 | 3.88 ± 2.782 *** | 1.32 | 0.659 **** | 0.719 **** |
| Carbohydrate (g) | 294.308 | 75.309 | 391.6 | 153.89 | 97.29 ± 125.3 *** | 1.53 | 0.610 **** | 0.518 **** |
| Energy (kcal) | 1980.38 | 510.561 | 2635.24 | 1001.03 | 654.86 ± 771.1 *** | 1.47 | 0.653 **** | n.a. |
| Calcium (mg) | 555.908 | 198.589 | 704.18 | 297.99 | 148.27 ± 2124 *** | 1.18 | 0.700 **** | 0.673 **** |
| Phosphorus (mg) | 1382.07 | 378.560 | 1841.33 | 696.25 | 459.26 ± 775.9 *** | 1.38 | 0.704 **** | 0.712 **** |
| Fat (g) | 61.6898 | 23.011 | 82.48 | 39.98 | 20.79 ± 29.59 *** | 1.29 | 0.681 **** | 0.510 *** |
| Riboflavin (mg) | 0.8389 | 0.3033 | 1.06 | 0.44 | 0.22 ± 1.691 | 1.14 | 0.719 **** | 0.656 *** |
| Chloride (mg) | 123.474 | 58.758 | 163.11 | 89.23 | 39.63 ± 75.93 *** | 1.15 | 0.537 **** | 0.598 **** |
| Sulfur (mg) | 110.734 | 70.087 | 143.79 | 96.35 | 33.05 ± 72.15 *** | 1.05 | 0.664 **** | 0.619 **** |
| Magnesium (mg) | 375.306 | 199.683 | 481.19 | 181.64 | 105.88 ± 218.2 *** | 0.70 | 0.346 | 0.413 |
| Choline (mg) | 167.922 | 77.856 | 212.45 | 97.18 | 44.52 ± 87.26 *** | 0.98 | 0.519 **** | 0.578 **** |
| Vitamin C (mg) | 81.758 | 45.350 | 105.84 | 54.58 | 24.08 ± 50.8 *** | 0.92 | 0.495 | 0.612 ** |
| Thiamine (mg) | 1.03178 | 0.3113 | 1.4 | 0.55 | 0.368 ± 1.453 *** | 1.30 | 0.673 **** | 0.553 *** |
| Iron (mg) | 13.4568 | 4.1980 | 18.28 | 7.82 | 4.82 ± 6.241 *** | 1.37 | 0.643 **** | 0.612 **** |
| Niacin (mg) | 14.728 | 4.0433 | 20.39 | 7.85 | 5.66 ± 6.285 *** | 1.19 | 0.613 **** | 0.654 **** |
| Carotene (μg) | 1173.29 | 2034.17 | 1201.26 | 876.2 | 27.97 ± 1877 | 1.40 | 0.385 | 0.418 |
| B6 (mg) | 0.4334 | 0.169 | 0.58 | 0.28 | 0.14 ± 1.809 | 0.42 | 0.712 **** | 0.678 *** |
| Folic Acid (μg) | 62.385 | 26.554 | 82.67 | 38.02 | 20.28 ± 24.65 *** | 1.23 | 0.716 **** | 0.617 *** |
| Sodium (mg) | 156.898 | 76.954 | 196.55 | 118.98 | 39.652 ± 88.76 *** | 1.08 | 0.666 **** | 0.719 **** |
| Potassium (mg) | 754.281 | 346.42 | 970.77 | 495.89 | 216.48 ± 353.1 *** | 1.23 | 0.703 **** | 0.652 *** |
| Copper(mg) | 1.512 | 6.775 | 1.65 | 1.03 | 0.138 ± 21.88 | 1.11 | 0.641 **** | 0.562 *** |
| Manganese (mg) | 3.252 | 1.099 | 4.45 | 1.85 | 1.198 ± 2.084 | 0.14 | 0.354 | 0.487 |
| Molybdenum (mg) | 0.336 | 0.115 | 0.44 | 0.18 | 0.104 ± 1.572 | 1.23 | 0.602 **** | 0.586 **** |
| Zinc (mg) | 5.5434 | 1.673 | 7.48 | 2.88 | 1.9366 ± 2.542 | 1.19 | 0.513 **** | 0.617 **** |
| Chromium (mg) | 0.0389 | 0.014 | 0.05 | 0.02 | 0.0111 ± 1.701 | 1.27 | 0.673 **** | 0.598 **** |
*** p < 0.001; **** p < 0.0001. SD, Standard deviation; n.a., not applicable; (r) unadjusted for energy intakes, (R) adjusted for energy intake