Development, validity and reliability of the first semi-quantitative Iranian toddler's food frequency questionnaire (T-FFQ) for diet-disease relations

Background: Only few food frequency questionnaires (FFQs) have been specifically designed and validated for toddlers. There is no valid instrument to assess usual intakes of Iranian toddlers. The present study was designed to develop a FFQ, and to examine its validity and reliability among toddlers to assess diet-disease relations.Material and methods: This cross-sectional study was conducted in ۲۰۱۹ in Isfahan, Iran. Mothers of ۱۰۰ toddlers completed a semi-quantitative FFQ with ۹۹ items as well as three nonconsecutive dietary records. Data on maternal age, education, toddler gender, birth order, birth weight, current weight and height, and the age of beginning complementary foods were collected. By comparing the results obtained from dietary records and the FFQ, we assessed the relative validity. Reliability was evaluated by intra-class correlation coefficients between results of two FFQs administered with four weeks intervals to the same participants (n=۲۰), as well as weighted kappa. The Bland-Altman plots were used to assess the level of agreement between two FFQs.Results: Mean and standard deviation (SD) of age was ۳۲.۷۱ (۴.۷۶) years and ۲۲.۴۲ (۳.۵۲) months, for mothers and toddlers, respectively. The FFQ showed acceptable validity andreliability. The correlation coefficients for the first FFQ were ۰.۸۲ (energy), ۰.۸۱ (fats), ۰.۶۰ (carbohydrate), ۰.۹۶ (calcium), ۰.۳۹ (iron) and ۰.۲۴ (vitamin C), all P-values were <۰.۰۰۱, except for vitamin C (P: ۰.۰۲). Reliability coefficients were between ۰.۷۷ (vitamin C) and ۰.۹۹ (calcium, potassium, phosphorus, zinc, riboflavin, vitamin B۱۲, vitamin E and D). The Cronbach's Alpha was ۰.۹۱, showing high reliability.Conclusion: The present study provided a thorough assessment of both validity and reliability of T-FFQ, and indicated acceptable validity as compared with three-day dietary records and good reliability. Therefore, this FFQ could be a useful tool to evaluate usual dietary intake of toddlers.