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Validation Information: Food4Me

Forster 2014

Online dietary intake estimation: the Food4Me food frequency questionnaire

Background: Dietary assessment methods are important tools for nutrition research. Online dietary assessment tools have the potential to become invaluable methods of assessing dietary intake because, compared with traditional methods, they have many advantages including the automatic storage of input data and the immediate generation of nutritional outputs.

Objective: The aim of this study was to develop an online food frequency questionnaire (FFQ) for dietary data collection in the "Food4Me" study and to compare this with the validated European Prospective Investigation of Cancer (EPIC) Norfolk printed FFQ.

Methods: The Food4Me FFQ used in this analysis was developed to consist of 157 food items. Standardized color photographs were incorporated in the development of the Food4Me FFQ to facilitate accurate quantification of the portion size of each food item. Participants were recruited in two centers (Dublin, Ireland and Reading, United Kingdom) and each received the online Food4Me FFQ and the printed EPIC-Norfolk FFQ in random order. Participants completed the Food4Me FFQ online and, for most food items, participants were requested to choose their usual serving size among seven possibilities from a range of portion size pictures. The level of agreement between the two methods was evaluated for both nutrient and food group intakes using the Bland and Altman method and classification into quartiles of daily intake. Correlations were calculated for nutrient and food group intakes.

Results: A total of 113 participants were recruited with a mean age of 30 (SD 10) years (40.7% male, 46/113; 59.3%, 67/113 female). Cross-classification into exact plus adjacent quartiles ranged from 77% to 97% at the nutrient level and 77% to 99% at the food group level. Agreement at the nutrient level was highest for alcohol (97%) and lowest for percent energy from polyunsaturated fatty acids (77%). Crude unadjusted correlations for nutrients ranged between .43 and .86. Agreement at the food group level was highest for "other fruits" (eg, apples, pears, oranges) and lowest for "cakes, pastries, and buns". For food groups, correlations ranged between .41 and .90.

Conclusions: The results demonstrate that the online Food4Me FFQ has good agreement with the validated printed EPIC-Norfolk FFQ for assessing both nutrient and food group intakes, rendering it a useful tool for ranking individuals based on nutrient and food group intakes.

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Validation Information

Year of Publication

Tool Information

Dietary Exposure Measured
Full Nutrient, Food Groups
Tool Type
Food Frequency Questionnaire
Timeframe Tool Measures info
1 Month
Portion Size Measures info
Reporting Method info
Usual; Retrospective
Format info
Supplements Measured
Administration Method info

Study Information

Study Location
Dublin, Ireland and Reading, England
Associated Nutrient Database
WISP Food composition databank (Tinuviel Software, Anglesey, UK) which uses McCance & Widdowson's The Composition of Foods, 5th & 6th editions and supplements.
Comparator Validated Against
Food Frequency Questionnaire


Sample Size
Age of Population

Mean(SD): 30(10.2) years

Other Notable Characteristics
Subjects were Reading, UK and Dublin, Ireland

Total number of nutrients validated: 22 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: 7
  • Micronutrients: 14
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
Food Frequency Questionnaire Adults Both Energy (kcal) 671 597 0.68 (S) 52 4 -523 1865
Protein (g) 21 29 0.63 (S) 46 4 -36 78
Fat (g) 23 27 0.70 (S) 46 4 -32 78
Saturated Fat (g) 11 12 0.71 (S) 46 4 -12 34
MUFA (g) 10 11 0.70 (S) 47 4 -11 31
PUFA (g) 2 6 0.56 (S) 39 4 -10 14
Carbohydrates (g) 85 75 0.63 (S) 55 4 -66 236
Total Sugars (g) 26 34 0.74 (S) 57 4 -42 94
Sodium (mg) 155.1 885.2 0.58 (S) 50 4 -1615 1926
Calcium (mg) 324.1 395.6 0.51 (S) 45 4 -467 1115
Iron (mg) 6.2 5.2 0.48 (S) 44 4 -4 17
Retinol (µg) 60 242.6 0.65 (S) 48 4 -425 545
Folate (µg) 125 115.7 0.53 (S) 49 4 -106 356
Vitamin B12 (µg) 1.3 3.1 0.49 (S) 39 4 -5 7
Vitamin C (mg) 57.4 63.8 0.69 (S) 52 4 -70 185

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.

Forster H, Fallaize R, Gallagher C, O'Donovan CB, Woolhead C, Walsh MC, et al. Online dietary intake estimation: the Food4Me food frequency questionnaire. Journal of medical Internet research. 2014;16(6):e150.