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Validation Information: Food Intake Questionnaire (FIQ)

Johnson 2001

An investigation of the validity and reliability of a food intake questionnaire

Aims: To evaluate the reliability and criterion validity of a food intake questionnaire (FIQ) designed for use in schoolchildren.

Methods: Study of reliability: 98 young people aged 13-14 years attending two schools in deprived areas of Liverpool completed the FIQ on three separate occasions over a 3-month period.

Validity study: Ninety-six young people (aged 11-13 years) completed the FIQ and 2 weeks later completed a 3-day food diary (with interview).

Results: The FIQ gave consistent response on separate occasions over the 3-month reliability study period. Levels of agreement were consistent between survey combinations. Analysis of variance showed no differences in mean score for food groups between surveys. Pearson correlations for mean scores estimated by separate FIQ ranged from 0.42 for fibre food group to 0.76 for negative marker food group; the majority of the correlations were above 0.5. The data suggested the FIQ should be able to detect a change of ±10% in eating habits. The validity study provided modest but significant Pearson correlations between energy intake, fat intake as a percentage of energy intake and sugars intake derived from 3-day diaries, and mean scores for the fatty, sugary and negative marker food group assessed by the FIQ.

Conclusions: The results from both studies provide an indication of the FIQ's reliability, and suggest it has criterion validity for fatty and sugary and negative marker foods.

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Validation Information

Year of Publication

Tool Information

Dietary Exposure Measured
Food Groups
Tool Type
Food Checklist
Timeframe Tool Measures info
1 Day
Portion Size Measures info
Not recorded
Reporting Method info
Format info
Supplements Measured
Not reported
Administration Method info

Study Information

Study Location
Liverpool, England
Associated Nutrient Database
The food diary used Microdiet version 9.1 which uses McCance & Widdowson's The Composition of Foods, 5th edition and supplements.
Comparator Validated Against
Food Diary Estimated


Sample Size
98 (both)
Age of Population

Range: 11-13 years

Other Notable Characteristics
Participants were involved in a school-based nutrition education programme in a secondary school.

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
Estimated Food Diary Adolescents Both

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.

Johnson B, Hackett A, Roundfield M, Coufopoulos A. An investigation of the validity and reliability of a food intake questionnaire. Journal of Human Nutrition and Dietetics. 2001 Dec 1;14(6):457-65.