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Validation Information: FFQ

Margetts 1989

Comparison of a Food Frequency Questionnaire with a Diet Record

The associations between levels of nutrients derived from a 24-hour diet record and a food frequency questionnaire were assessed in a sample of 433 men and women. The food frequency questionnaire was administered three years after the completion of the diet record. Spearman correlations were all statistically significant; they varied from 0.36 for energy to 0.15 for vitamin A. Comparison of distributions into fifths showed few people grossly misclassified. A model was developed to assess the correlations which would be expected under various conditions of within and between subject variance for each nutrient, errors in measurements and drift in intake over time. The best possible correlation that could be obtained using the within and between subject variations in intake previously published, and with no measurement error or drift over time, was 0.60 for energy and 0.34 for vitamin A. Using a realistic measure of measurement error (standard deviation on log scale of 0.12 for diet record method, 0.06 for drift over time and 0.18 for food frequency method) the correlations obtained in the modelling were very similar to that observed. This study shows that it may be appropriate to use a food frequency questionnaire instead of a diet record to estimate intakes in population based epidemiological studies.

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Validation Information

Year of Publication

Tool Information

Dietary Exposure Measured
Full Nutrient
Tool Type
Food Frequency Questionnaire
Timeframe Tool Measures info
Month (s)
Portion Size Measures info
Usual portion sizes from Bingham and Day (1987).
Reporting Method info
Usual; Retrospective
Format info
Supplements Measured
Not Reported
Administration Method info

Study Information

Study Location
Ipswich, Stoke and Wakefield, England
Associated Nutrient Database
McCance & Widdowson's The Composition of Foods, 4th edition
Comparator Validated Against
24hr Recall


Sample Size
Age of Population

Range: 35-54 years

Other Notable Characteristics
Subjects were recruited from participants in a larger study of diet and health in three English towns

Total number of nutrients validated: 9 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.

  • Energy
  • Macronutrients: 4
  • Micronutrients: 4
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 Both Energy (kcal) 0.36 (S) 27 5
Energy (kJ) 0.36 (S) 27 5
Protein (g) 0.22 (S) 24 5
Fat (g) 0.36 (S) 26 5
Carbohydrates (g) 0.30 (S) 24 5
Calcium (mg) 0.21 (S) 23 5
Vitamin C (mg) 0.24 (S) 24 5

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.

Margetts BM, Cade JE, Osmond C. Comparison of a food frequency questionnaire with a diet record. International Journal of Epidemiology. 1989 Dec 1;18(4):868-73.