Validity of a modified food and nutrition literacy questionnaire in primary school children in Iran

The present study aimed to assess the relative validity and reliability of a modified Food and Nutrition Literacy (M-FNLIT) questionnaire in primary school children in the city of Mashhad. The study was conducted in four phases. In the first step, the content and face validity of the questionnaire were evaluated by Delphi consensus as well as interviewing the students. Then, construct validity was examined using Confirmatory Factor Analysis (CFA). The internal consistency and reliability of the questionnaire were also assessed using Cronbach a and Intraclass Correlation Coefficient (ICC), respectively. Finally, a receiver operating characteristic analysis was performed to detect the cut-off scores of the M-FNLIT scale. Findings of two rounds of Delphi showed satisfactory levels of Content Validity Ratio: 0.72 and 0.92, Content Validity Index (CVI): 0.92 and 0.98, respectively. The results of CFA for domains and subscales of the M-FNLIT questionnaire including cognitive domain (understanding food and nutrition information and nutritional health knowledge) and skill domain (functional, food choice, interactive, and critical skills) indicated acceptable fit indices. M-FNLIT subscale-specific Cronbach a values ranged between 0.68 and 0.8 and ICC was 0.95 (95 % CI 0.93, 96). The final questionnaire included forty items (thirty-six Likert-type and four true-false items). FNLIT scores were categorized as low (<= 58), medium (> 58-< 81), and high (>= 81). The M-FNLIT questionnaire has a good level of validity and reliability to measure food and nutrition literacy in primary school children. The questionnaire can be applied in the evaluation of nutritional interventions in this age group.