Relative Validity and Reproducibility of a Semi-quantitative Food Frequency Questionnaire among Urban Iranians

The contribution of dietary factors to the development and prevention of non-communicable diseases is being increasingly recognized and the worldwide concern about chronic diseases is growing rapidly. Due to lack of a comprehensive food frequency questionnaire (FFQ) encompassing all kinds of foods for Iranians, this cross-sectional study aims to describe the relative validity and reproducibility of the FFQ used for assessing nutrient intakes of Iran urban population. One hundred thirteen subjects aged 20-69 years old from five major cities of Iran participated in this study. Dietary intake was assessed by a semi-quantitative FFQ involving 160 Iranian food items. Participants were asked to complete two FFQs (at the first and fourth months of the study) and three-day food records every month. Two blood and 24-h urine samples were collected at fifth and sixth months. The highest correlation coefficient in all FFQs was for fat (r=0.669; p