A comparison of dietary intake estimates in a population with chronic renal failure

The present study compares estimates of dietary intake of 40 patients with chronic renal failure. The study uses the modified diet history technique and a semiquantitative food frequency questionnaire. Both methods are used by a registered dietitian during personal interviews with the patients. Significantly more food items are recalled and significantly greater estimates of all nutrients tested (except cholesterol) are obtained using the food frequency questionnaire. Furthermore, results with this technique are more consistent with typical dietary intake for the Israeli population. Bias in patients' reporting of dietary intake causes the outcome of dietary intervention and evaluation of patient compliance difficult to assess. The food frequency questionnaire seems to produce less misclassification bias and therefore, may better estimate true dietary intake in patients with chronic renal failure.