Dietary intake estimated using different methods in two Italian older populations

Most of the tools used to assess nutritional intake in large epidemiological studies were originally developed to be used in young and middle-aged subjects and, therefore, their validity and reliability when employed in older subjects remain uncertain. We conducted this study to verify whether the questionnaire developed in the context of the European Prospective Investigation into Cancer and nutrition (EPIC) could be used to assess dietary intake in the participants of InCHIANTI, an epidemiological study of risk factors for disability in late life, performed in 633 men (78% aged, ≥65 years) and 802 women (81% aged, ≥65 years) randomly sampled from the general population. In particular, the aim of this project was to collect preliminary information that could support a future study of concurrent validity. Data on food consumption assessed using the EPIC questionnaire from the InCHIANTI participants were compared with those collected using a 7-day diary in the National Nutritional Investigation into Dietary Behavior (INN-CA), a study conducted in 15 Italian centres aimed at assessing Italian households' and individuals' dietary intake. In spite of different populations and different methods used in data collection, the distributions of dietary intake from the two studies were remarkably similar for most macro- and micro-nutrients, both in men and women and according to age groups. At a population level, a food frequency questionnaire and a costly and time-consuming objective method provided similar estimates of dietary intake. Future study should attempt to generalize these findings at an individual level by collecting data with both instruments in the same subjects.