Table 4.
Test–retest reliability: Difference and intra-class correlation between daily energy intake estimates from processed food categories between both FFQ administrations (n = 99).
| FFQ1 Mean (SD) | FFQ2 Mean (SD) | Mean Difference (95% CI) between both FFQ Administrations | p-Value | 95% Limits of Agreement | Intra-Class Correlation Coefficient | |
|---|---|---|---|---|---|---|
| MPF | ||||||
| EI (kJ) | 2802 (971) | 2564 (855) | −239 (−373, −104) | 0.001 | 0 to 1108 | 0.73 |
| EI (%) | 39.1 (8.4) | 37.9 (9.4) | −1.2 (−2.6, 0.2) | 0.102 | −15.6 to 13.2 | 0.67 |
| PCI | ||||||
| EI, kJ | 44.2 (58.3) | 36.9 (34.0) | −7.3 (−16.7, 2.2) | 0.129 | −102 to 87 | 0.51 |
| EI, % | 0.63 (0.74) | 0.56 (0.55) | −0.07 (−0.18, 0.04) | 0.196 | −1.1 to 1.0 | 0.64 |
| PF | ||||||
| EI, kJ | 243 (142) | 240 (119) | −3 (−25, 19) | 0.764 | −223 to 217 | 0.65 |
| EI, % | 3.4 (1.9) | 3.6 (1.7) | 0.1 (−0.1, 0.4) | 0.336 | −2.6 to 2.9 | 0.70 |
| UPF | ||||||
| EI, kJ | 4102 (1393) | 4003 (1427) | −99 (−295, 97) | 0.319 | 0 to 1868 | 0.76 |
| EI, % | 56.8 (8.6) | 58.0 (9.3) | 1.1 (−0.4, 2.6) | 0.141 | −14.0 to 16.3 | 0.64 |
Abbreviations: EI, energy intake; FFQ, food frequency questionnaire; kJ, kilojoules; MPF, minimally processed food; PCI, processed culinary ingredient; PF, processed food; UPF, ultra-processed food.