Validity and reliability of a new food frequency questionnaire compared to 24 h recalls and biochemical measurements: pilot phase of Golestan cohort study of esophageal cancer

Eur J Clin Nutr. 2006 Aug;60(8):971-7. doi: 10.1038/sj.ejcn.1602407. Epub 2006 Feb 8.


Background: A pilot study was carried out to evaluate validity and reproducibility of a food frequency questionnaire (FFQ), which was designed to be used in a prospective cohort study in a population at high risk for esophageal cancer in northern Iran.

Methods: The FFQ was administered four times to 131 subjects, aged 35-65 years, of both sexes. Twelve 24-h dietary recalls for two consecutive days were administered monthly during 1 year and used as a reference method. The excretion of nitrogen was measured on four 24-h urine samples, and plasma levels of beta-carotene, retinol, vitamin C and alpha-tocopherol was measured from two time points. Relative validity of FFQ and 24-h diet recall was assessed by comparing nutrient intake derived from both methods with the urinary nitrogen and plasma levels of beta-carotene, retinol, vitamin C and alpha-tocopherol.

Results: Correlation coefficients comparing energy and nutrients intake based on the mean of the four FFQ and the mean of twelve 24-h diet recalls were 0.75 for total energy, 0.75 for carbohydrates, 0.76 for proteins and 0.65 for fat. Correlation coefficients between the FFQ-based intake and serum levels of beta-carotene, retinol, vitamin C and vitamin E/alpha-tocopherol were 0.37, 0.32, 0.35 and 0.06, respectively. Correlation coefficients between urinary nitrogen and FFQ-based protein intake ranged from 0.23 to 0.35. Intraclass correlation coefficients used to measure reproducibility of FFQ ranged from 0.66 to 0.89.

Conclusion: We found that the FFQ provides valid and reliable measurements of habitual intake for energy and most of the nutrients studied.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Adult
  • Aged
  • Cohort Studies
  • Diet Surveys
  • Diet*
  • Dietary Carbohydrates / administration & dosage
  • Dietary Fats / administration & dosage
  • Dietary Proteins / administration & dosage
  • Energy Intake / physiology
  • Esophageal Neoplasms / blood
  • Esophageal Neoplasms / epidemiology*
  • Esophageal Neoplasms / urine
  • Female
  • Humans
  • Iran / epidemiology
  • Male
  • Mental Recall
  • Middle Aged
  • Nitrogen / urine*
  • Pilot Projects
  • Prospective Studies
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Surveys and Questionnaires / standards*
  • Vitamins / blood*


  • Dietary Carbohydrates
  • Dietary Fats
  • Dietary Proteins
  • Vitamins
  • Nitrogen