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Table 6 Reproducibility of food frequency questionnaire for energy and nutrient intakes

From: Development and validation of a food frequency questionnaire for Japanese athletes (FFQJA)

Nutrient intakes   1st FFQJA 2nd FFQJA Correlation coefficient
Median (Interquartile range) Median (Interquartile range) Crude (95% CI) Energy-adjusted (95% CI) ICC (95% CI)
Energy (kcal) 2503 (2065, 3416) 2536 (2051, 3098) 0.597 (0.313–0.783) 0.619 (0.373–0.784)
Protein (g) 91.7 (66.8, 116.0) 95.1 (71.2, 111.9) 0.663 (0.403–0.824) 0.644 (0.376–0.812) 0.623 (0.379–0.787)
Fat (g) 73.6 (58.4, 94.0) 69.5 (50.8, 86.8) 0.689 (0.440–0.840) 0.631 (0.358–0.804) 0.606 (0.354–0.775)
Carbohydrate (g) 402.2 (311.5, 512.5) 362.5 (291.4, 439.9) 0.582 (0.293–0.773) 0.563 (0.269–0.761) 0.588 (0.330–0.764)
Calcium (mg) 588 (422, 811) 488 (412, 783) 0.604 (0.322–0.788) 0.421 (0.098–0.664) 0.634 (0.406–0.799)
Iron (Fe) (mg) 7.9 (5.9, 10.6) 8.4 (6.1, 9.8) 0.721 (0.487–0.858) 0.654 (0.390–0.819) 0.735 (0.542–0.854)
Retinola (ηgRAE) 540 (362, 960) 581 (422, 990) 0.633 (0.361–0.806) 0.597 (0.390–0.819) 0.689 (0.474–0.827)
Vitamin B1 (mg) 1.30 (0.89, 1.79) 1.17 (1.01, 1.67) 0.654 (0.390–0.819) 0.577 (0.287–0.770) 0.634 (0.394–0.793)
Vitamin B2 (mg) 1.48 (1.02, 1.85) 1.35 (1.03, 1.92) 0.743 (0.521–0.871) 0.562 (0.267–0.761) 0.721 (0.521–0.846)
Vitamin C (mg) 103 (59, 174) 122 (68, 159) 0.737 (0.521–0.868) 0.745 (0.524–0.872) 0.752 (0.569–0.864)
Dietary fiber (g) 12.3 (10.0, 16.4) 11.5 (9.1, 16.0) 0.654 (0.390–0.819) 0.679 (0.425–0.834) 0.755 (0.574–0.866)
  1. n = 36
  2. FFQJA Food frequency questionnaire for Japanese athletes
  3. Crude correlation coefficient: Spearman’s correlation coefficients
  4. Energy-adjusted correlation coefficients were calculated using an energy density method
  5. ICC Intraclass correlation coefficients
  6. a Retinol was calculated as retinol activity equivalents (RAE: retinol activity equivalents)
  7. 95% CI: 95% confidence interval