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Validation Information: FFQ (I) (Food groups)

Ocke 1997

The Dutch EPIC Food Frequency Questionnaire. I. Description of the Questionnaire, and Relative Validity and Reproducibility for Food Groups

Background. A self-administered food frequency questionnaire was developed for the Dutch cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC). Habitual consumption of 178 food items can be calculated from the questionnaire data.

Methods. Reproducibility and relative validity for food group intake were investigated in a population of 121 Dutch men and women. The questionnaire was administered three times at 6-month intervals in order to determine the reproducibility. To assess the relative validity 12 monthly 24-hour recalls served as the reference method.

Results. Spearman rank order correlation coefficients between estimates of food group intake assessed by repeated questionnaires ranged from 0.45 to 0.92. For men, Spearman correlation coefficients between estimates of food group intake based on the questionnaire and those based on 24-hour recalls ranged from 0.21 for cooked vegetables to 0.78 for sugar and sweet products, with a range of 0.61. For women the median was 0.53, with a minimum of 0.31 for vegetables and a maximum of 0.87 for alcoholic beverages. The photographs in the questionnaire for the estimation of portion sizes contributed little to the relative validity of the ranking of subjects. However, on the group level most median food group estimates based on photographic portion sizes were closer to the median intakes as assessed by 24-hour recalls than those based on standard portion sizes.

Conclusions. The questionnaire seems adequate for ranking Dutch EPIC subjects according to intake of most food groups, although the relative validity for some food groups, such as vegetables and fish, remains of concern.

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Validation Information

Year of Publication

Tool Information

Dietary Exposure Measured
Food Groups
Tool Type
Food Frequency Questionnaire
Timeframe Tool Measures info
1 year
Portion Size Measures info
Portion sizes were either specified in household units or shown in colour photographs taken by a professional food photographer
Reporting Method info
Format info
Supplements Measured
Administration Method info

Study Information

Study Location
The Netherlands
Associated Nutrient Database
Adapted computerised version of the 1993 Dutch Food Composition Table
Comparator Validated Against
24hr Recall


Sample Size
63 (Male), 58 (Female)
Age of Population

Mean (SD): 42.6 (11.1) years

Male Only, Female Only
Other Notable Characteristics
Subjects were recruited from towns in the Netherlands from ongoing projects. The questionnaire assessed food group intake where vegetable intake comparison was assessed.

Total number of nutrients validated: 0 info

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.

  • Macronutrients: 0
  • Micronutrients: 0
Comparator Lifestage Sex Nutrient Measured info Mean Difference Standard Deviation info Correlation Coefficient info Cohen's Kappa Coefficient Percentage Agreement Percentage Agreement Categories info Lower Limits of Agreement Upper Limits of Agreement
24hr Recall Adults Male Only Fruits 5 (Median) 0.68 (S)
Vegetables -3 (Median using standard portion size calc) 0.38 (S)
24hr Recall Adults Female Only Fruits 19 (Median) 0.56 (S)
Vegetables 38 (Median using standard portion size calc) 0.31 (S)

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.

Ocke M C, Bueno-De-Mesquita H Bas, Goddijn H Ester, Jansen A M, Pols M A, Van Staveren W A. & Kromhout D. (1997). The Dutch EPIC Food Frequency Questionnaire .1. Description of the Questionnaire, and Relative Validity and Reproducibility for Food Groups. International Journal of Epidemiology, 26 (1) supp 1