Validity and reproducibility of a self-administered semi-quantitative food-frequency questionnaire for estimating usual daily fat, fibre, alcohol, caffeine and theobromine intakes among Belgian post-menopausal women

Int J Environ Res Public Health. 2009 Jan;6(1):121-50. doi: 10.3390/ijerph6010121. Epub 2009 Jan 6.


A novel food-frequency questionnaire (FFQ) was developed and validated to assess the usual daily fat, saturated, mono-unsaturated and poly-unsaturated fatty acid, fibre, alcohol, caffeine, and theobromine intakes among Belgian post-menopausal women participating in dietary intervention trials with phyto-oestrogens. The relative validity of the FFQ was estimated by comparison with 7 day (d) estimated diet records (EDR, n 64) and its reproducibility was evaluated by repeated administrations 6 weeks apart (n 79). Although the questionnaire underestimated significantly all intakes compared to the 7 d EDR, it had a good ranking ability (r 0.47-0.94; weighted kappa 0.25-0.66) and it could reliably distinguish extreme intakes for all the estimated nutrients, except for saturated fatty acids. Furthermore, the correlation between repeated administrations was high (r 0.71-0.87) with a maximal misclassification of 7% (weighted kappa 0.33-0.80). In conclusion, these results compare favourably with those reported by others and indicate that the FFQ is a satisfactorily reliable and valid instrument for ranking individuals within this study population.

Keywords: Food-frequency questionnaire; estimated diet record; fat; fibre; reproducibility; validity.

Publication types

  • Clinical Trial

MeSH terms

  • Aged
  • Alcohol Drinking
  • Belgium
  • Caffeine
  • Diet Records*
  • Diet*
  • Dietary Fats
  • Dietary Fiber
  • Female
  • Humans
  • Middle Aged
  • Postmenopause
  • Reproducibility of Results
  • Surveys and Questionnaires
  • Theobromine


  • Dietary Fats
  • Dietary Fiber
  • Caffeine
  • Theobromine