Online Version of the Self-Administered Food Frequency Questionnaire for the Iranian Adult Population

With the growing accessibility of the internet, dietary assessment tools, including food frequency questionnaires (FFQs), are increasingly being adapted for web platforms. A web-based FFQ was developed as a dietary assessment tool for healthy adults in Iran.

This study aimed to develop an online FFQ for dietary data collection among Iranian adults and to compare its performance with the validated Iranian printed FFQ.

Eligible participants were randomly assigned to complete both the printed and web-based FFQs. The type of FFQ alternated for each participant after 10 days. The agreement between the two FFQs was assessed using the Bland-Altman method and correlation analysis.

Of the 190 participants, final analyses were conducted on 141 individuals, including 70 females (49.6%) and 71 males (50.4%) who completed both FFQs. Agreement was high for all nutrient intakes (r > .8). Among food groups, "Whole grains" showed the highest correlation (r = .84), while "Potato" had the lowest (r = .25). There were no significant differences in the time taken to complete the questionnaires.

The web-based FFQ demonstrated strong agreement with the validated printed FFQ, accurately reflecting nutrient and food group intakes in Iranian adults.