Validation Information: UK EPIC FFQ
Lietz 2002
Can the EPIC food-frequency questionnaire be used in adolescent populations?
Objective: To assess the validity of the food-frequency questionnaire used in the European Prospective Investigation of Cancer (EPIC FFQ) for estimating nutrient intake in an adolescent population.
Design: Sixty even schoolchildren (mean age: 12:3 ± 0:3 years) were recruited to complete a 7-day weighed dietary record (7-day WDR), the EPIC FFQ and supply one 24 hour urine collection. Setting: Harris Academy in Dundee (UK).
Results: Fifty subjects completed both dietary assessment methods. Thirteen of these were classified as underreporters with energy intake/basal metabolic rate < 1:14. The EPIC FFQ showed higher estimates than the 7-day WDR for all nutrients. The median Spearman correlation coefficient for the nutrients examined was found to be 0.31 and increased to 0.48 after adjustment for total energy. The limits of agreement were as far apart as 13.4 MJ, 120 g, 270 g, 120 g and 1170 mg for energy, fat, sugar, protein and calcium, respectively. Correlations between urine and 7-day WDR dietary nitrogen and potassium were found to be statistically significant with r = 0:45 (P < 0:05) and r = 0:78 (P < 0:001), respectively. The median proportion of subjects that appeared in the same and opposite third of intake was found to be 45.9% and 10.8%, respectively.
Conclusions: The EPIC FFQ seems adequate to correctly classify low, medium and high consumers and might therefore be used to identify adolescent population groups at risk or for differences between populations. However, agreement between the EPIC FFQ and the 7-day WDR was very poor on both a group and an individual basis, and demonstrates that the EPIC FFQ is not an appropriate method for estimating absolute intakes in this age group.
Total number of nutrients validated: 9
Not all of the nutrients validated in the validation studies are included in the table below, as statistical data was only selected to be displayed for a number of nutrients, this included:
- Energy
- Fat
- Saturated Fat
- Mono-unsaturated Fat
- Poly-unsaturated Fat
- Carbohydrates
- Protein
- Sugar
- Non‐starch polysaccharides(NSP)
- Sodium
- Calcium
- Iron
- Zinc
- Retinol
- Folate
- Folic Acid
- Vitamin B12
- Vitamin C
- Fruit & Vegetables
- Urinary Nitrogen
To find information on the other validated nutrients please read the validation study.
- Energy
- Macronutrients: 5
- Micronutrients: 3
| Comparator | Lifestage | Sex | Nutrient Measured | Mean Difference | Standard Deviation | Correlation Coefficient | Cohen's Kappa Coefficient | Percentage Agreement | Percentage Agreement Categories | Lower Limits of Agreement | Upper Limits of Agreement |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Weighed Food Diary | Adolescents | Both | Energy (kcal) | 574 | 717 | 0.33 (S) | 40.5^ | 3 | -956 | 1912 | |
| Energy (kJ) | 2400 | 3000 | 0.33 (S) | 40.5^ | 3 | -4000 | 8000 | ||||
| Protein (g) | 31 | 29 | 0.30 (S) | 40.5^ | 3 | -27 | 89 | ||||
| Fat (g) | 22 | 35 | 0.52 (S) | 45.9^ | 3 | -49 | 92 | ||||
| Carbohydrates (g) | 69 | 118 | 0.28 (S) | 48.6^ | 3 | -167 | 305 | ||||
| Total Sugars (g) | 53 | 74 | 0.33 (S) | 37.8^ | 3 | -94 | 200 | ||||
| Fibre (NSP) (g) | 7 | 8 | 0.28 (S) | 45.9^ | 3 | -8 | 23 | ||||
| Sodium (mg) | 1134 | 1290.3 | 0.29 (S) | 37.8^ | 3 | -1446.5 | 3714.5 | ||||
| Calcium (mg) | 203 | 305 | 0.34 (S) | 37.8^ | 3 | -393 | 799 | ||||
| Biomarkers | Adolescents | Both | Urinary Nitrogen (g) | 8.1 | 5.9 | -0.20 (S) | -3.5 | 19.7 |
Some results have been calculated using statistical techniques based on the published data.
For further information on statistical terms click on Statistical tests used in validation studies
All correlations coefficients in the table are unadjusted unless stated otherwise. For adjusted correlation coefficients and other statistical methods used in the study e.g. paired t-tests, please read the validation articles.
- # Adjusted
- † Energy adjusted.
- ‡ For loge-transformed, energy-adjusted nutrient intakes.
- ^ Adjacent included.
- ᵟ Participants provided identical responses.
- (w) = Weighted.
Lietz G, Barton KL, Longbottom PJ, Anderson AS. Can the EPIC food-frequency questionnaire be used in adolescent populations?. Public Health Nutrition. 2002 Dec 1;5(06):783-9.