[Validation of a short questionnaire on frequency of dietary intake: reproducibility and validity].

Background: Knowledge on dietary intake in individuals is an essential tool to know the dietary patterns and explore their association with the disease risk. One of the current methods most currently used are dietary intake questionnaires. The main drawback of their use is the need for previous validation. Our objective was to validate a short questionnaire on the frequency of dietary intake.

Setting: Reus (Catalonia), Spain.

Subjects: 71 adolescents and adults from both genders, with different socio-cultural levels and professional categories.

Interventions: The questionnaire was administered two times within an approximated period of one year to assess the reproducibility. Through this time, 9 24-hour recalls (gold standard method) were administered to determine the validity.

Results: Spearman's correlation coefficients for the reproducibility analysis varied 0.49-0.75 for foods and 0.44-0.78 for energy and nutrients. Most of intra-class correlation coefficients varied 0.53-0.96 for foods and 0.49-0.78 for energy and nutrients. In the validity analysis, the correlations varied 0.27-0.59 for foods, and 0.30-0.49 for energy and nutrients. The correlation coefficients in the validity study varied 0.41-0.67 for foods, and 0.29-0.47 for energy and nutrients.

Conclusion: The questionnaire allows assessing the consumption of groups of foods, energy and macronutrients with adequate reproducibility and validity.