A novel system for collecting longitudinal self-reported dietary consumption information: The internet data logger (iDL)

As diet has been considered as the major exposure pathway for toxic chemicals, such as heavy metals and pesticides, we have developed a web-based questionnaire system, the internet data logger (iDL), in order to facilitate the collection of detailed self-recording of standardized daily dietary consumption. An iDL prototype optimized for hand-held devices was tested in the on-going Children's Pesticide Exposure Study (CPES) in Atlanta, GA in which 15 consecutive days of dietary consumption information were recorded by 11 children or their parents and transmitted to a server via broadband wireless internet connection. Participants spent an average of 6.2 min in day 1 to enter a meal into iDL and approximately 4 min per meal for the remaining 14 study days. Approximately 75% of 446 total meals were entered into iDL on the date of consumption. A within-person comparison revealed that many food items recorded on paper diary were later classified as “unknown” according to iDL standards due to the lack of detailed information provided by the participants. The development of iDL represents a novel and pioneering tool, which integrates dietary data collection, transmission, and management in a real-time and automated manner. iDL provides the needed flexibility and mobility for research focused on collecting not only dietary consumption data but also other time-sensitive behavior data. This study has demonstrated that iDL can be deployed to collect long-term dietary consumption information in a population-based study, though future modifications/enhancements will undoubtedly improve its usability and application.