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Validation Information: FFQ (Dietary total antioxidant capacity)

Pellegrini 2007

Development and Validation of a Food Frequency Questionnaire for the Assessment of Dietary Total Antioxidant Capacity Frequency Questionnaire for the Assessment of Dietary Total Antioxidant Capacity

The total antioxidant capacity (TAC) of the diet may be an important tool to monitor the protective effect of plant foods in epidemiological studies. We developed a semi-quantitative FFQ for the assessment of dietary TAC by 3 different assays,

i.e., Trolox equivalent antioxidant capacity (TEAC), total radical-trapping antioxidant parameter (TRAP) and ferric reducing antioxidant power (FRAP). The FFQ consists of 53 questions about the major sources of dietary TAC in Northern Italy and was validated against a 3-d weighed food record (3D-WR) in 285 individuals (159 males and 126 females) aged 35–88 y and living in the province of Parma (Italy). Plasma TAC was also evaluated in a subgroup of subjects using the TEAC and FRAP assays. The FFQ was associated with 3D-WR (quadratic-weighted k ¼ 0.49 for TEAC, 0.53 for TRAP, and 0.49 for FRAP; P <0.0001) and proved reasonably accurate to classify individuals into quartiles of TAC intake. The FFQ had a good repeatability when re-administered after 1 y in 55 subjects (quadratic-weighted k for intertitle agreement ¼ 0.66 for TEAC, 0.70 for TRAP and 0.68 for FRAP; P < 0.0001). With both dietary instruments, the main contributors to TAC intake were coffee and tea in women and alcoholic beverages in men, followed by fruits and vegetables in both sexes. Plasma TAC and dietary TAC were not associated. In conclusion, our FFQ has the potential for being used to rank subjects on the basis of their antioxidant intake as determined by dietary TAC in large epidemiological studies. The FFQ should be validated in external populations before being used for research purposes.

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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
3 months
Portion Size Measures info
Portion sizes were estimated using pictures of different size categories
Reporting Method info
Format info
Supplements Measured
Administration Method info

Study Information

Study Location
Parma, Italy
Associated Nutrient Database
Not reported
Comparator Validated Against
Weighed Food Diary


Sample Size
159 (Male), 126 (Female)
Adults (aged 35-88 years)
Age of Population
Not reported
Male Only, Female Only
Other Notable Characteristics
Subjects were previous and current workers from the Barilla food company in Parma, Italy. Participant screening and exclusion criteria relating to particular medical conditions was applied.The study did not assess nutrient intake.

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
Weighed Food Diary Adults (aged 35-88 years) Male Only Fruits -58.3 (Median)
Vegetables -17 (Median)
Weighed Food Diary Adults (aged 35-88 years) Female Only Fruits -41.7 (Median)
Vegetables 27.7 (Median)

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.

Pellegrini N, Salvatore S, Valtuena S, Bedogni, G, Porrini M, Pala V, Del Rio D, Sieri, S, Miglio, C, Krogh, V, Zavaroni I & Brighenti F. Development and Validation of a Food Frequency Questionnaire for the Assessment of Dietary Total Antioxidant Capacity. (2007). The Journal of Nutrition.137. 93-98