Comparison of two methods for dietary assessment : Diet history questionnaire and weighed food record

A comparison was made between the dietary intakes of 36 healthy adults, determined by a modified version of the diet history and a 3-day weighed record. In general, the dietary history questionnaire showed a higher intake than the food record. Significant differences (Wilcoxon test) were found for energy, protein, fat, carbohydrate, fibre, saturated fat and vitamin A. The differences in the median values estimated with the two methods were within 12% for all the variables, except for vitamin A. Intraclass correlation coefficients showed that energy, protein, fat, carbohydrate and alcohol [r i = 0.71-0.90) were in accordance in the two methods, while thiamin and vitamin A differed. On average, 61% of the subjects were classified in the same tertile in the diet history questionnaire and the 3-day record, and 5% in the opposite tertiles. By comparing the two methods it seems that the questionnaire was able to evaluate the differences in the nutrient intake.