Validation of Diet History Questionnaire in Assessing Energy and Nutrient Intakes of Iranian Population

Background: This study described validity of Diet History Questionnaire (DHQ) for assessing energy and nutrient intake among Iranian population. Methods: A group of experienced nutritionists translated the DHQ to Farsi language and modified it based on Iranian food habits and cooking methods. We recruited 244 healthy adults with a mean age of 42.83 +/- 0.75 yrs. from healthy individuals who were friends or relatives of patients in the Cancer Institute of Iran from April 2011 to February 2012. We used the DHQ to assess dietary intakes through interviews as well as at least four 24-h recalls one in every season. Reliability was estimated by comparing data of DHQ with mean intake from 24-hour recalls using deattenuated and energy-adjusted Spearman correlation coefficients. We classified dietary intakes of two methods into three groups to probe if DHQ correctly allocates subjects into different intake groups compared to reference method. The results are reported as percent of disagreement, adjacent agreement, and complete agreement. Results: Deattenuated Spearman correlation ranged from 0.18 for vitamin B-12 and fat to 0.60 for sugar. It ranged from 0.13 for pantothenic acid to 0.60 for sugar in men and from 0.07 for fat to 0.58 for sugar in females. The complete agreement of methods ranged from 51% for selenium to 36% for carotene in the entire sample, from 50% for energy to 31% for niacin in males and from 49% for sugar to 27% for vitamin B-12 in females. Conclusion: The DHQ is a valid tool for assessing most nutrients intake among Iranian population. In addition, it is a proper instrument in categorizing individuals based on their dietary intakes.