Background
High sodium intake has been linked to negative health effects, including cardiovascular and renal diseases. Traditional dietary sodium assessment methods are time-consuming and subjected to errors. Using technology may increase the efficiency and accuracy of dietary assessment. The objective of this study is to develop and validate a food frequency questionnaire (FFQ) screener using software to assess sodium intake among the Palestinian population. Methodology: The study was conducted in four phases. In Phase 1, Palestinian foods were categorized and subcategorized according to their mode of consumption, sodium content, and food groups. The sodium content values were calculated from Palestinian food composition database. Content validity was done in Phase 2, while in Phase 3, a pilot study was conducted to determine test-retest reliability. In Phase 4, the criterion validity of the screener was assessed by comparing the results of sodium intake from the FFQ screener with the results from a 24-hour urinary sodium test and a 3-day diet recall. Correlations between the sodium intake values from the three methods were analyzed using Pearson correlation tests, and the difference was assessed using the Bland-Altman test.
Results
The developed FFQ screener sodium screener included 41 food items categorized into nine groups, with photo-based portion size estimation and frequency of consumption. The reliability test showed a Pearson correlation coefficient of 0.7, p < 0.01 using test and retest. For criterion validity, the correlation coefficient between dietary sodium intake using the FFQ screener software and the 24-hour urine sodium test was (0.6, p < 0.000). The correlation coefficient between dietary sodium intake using the FFQ screener software and dietary sodium intake using a 3-day recall was (0.3, p < 0.000). Sodium intake was significantly correlated with preferences for low-sodium food and previous salt reduction, p < 0.05.
Conclusions
Using the FFQ screener software was a valid and reliable method for assessing dietary sodium intake. Using the photo-based method to estimate portion size improved precision and accuracy in diet assessment.