Meal distribution, relative validity and reproducibility of a meal-based food frequency questionnaire in Taiwan.

Food frequency questionnaire is an important assessment tool for public health nutrition research. We describe the development history and conducted the validity and reproducibility studies for a meal-based Chinese food frequency questionnaire (Chinese FFQ) by five meal sequences. A total of 51 subjects were recruited to collect dietary information twice (6 months apart) with one 24-hr recall, 7-day food records and the Chinese FFQ. Combining data from both time sets, Chinese FFQ showed strong correlations of macro and micronutrients with 7-day records (n = 60, r = 0.29-0.50, p < 0.05), but not with 24-hr recalls (n = 60, r = 0.01-0.23, p > 0.05). The reproducibility of this Chinese FFQ (n = 22) was consistently high for most nutrients, with Spearman correction coefficients between 0.42 for vitamin A to 0.79 for vitamin B12. From a larger sample of 231 subjects who completed the Chinese FFQ and one 24-hr recall, we found the energy distributions of breakfast, lunch, dinner, afternoon and evening snacks combined from Chinese FFQ were 20%, 37%, 37% and 6%, and from 24-hour recalls were 19%, 36%, 44% and 1%, respectively. These results showed acceptable reproducibility and relative validity of this meal-based Chinese FFQ.