Review and evaluation of innovative technologies for measuring diet in nutritional epidemiology

The use of innovative technologies is deemed to improve dietary assessment in various research settings. However, their relative merits in nutritional epidemiological studies, which require accurate quantitative estimates of the usual intake at individual level, still need to be evaluated. To report on the inventory of available innovative technologies for dietary assessment and to critically evaluate their strengths and weaknesses as compared with the conventional methodologies (i.e. Food Frequency Questionnaires, food records, 24-hour dietary recalls) used in epidemiological studies. A list of currently available technologies was identified from English-language journals, using PubMed and Web of Science. The search criteria were principally based on the date of publication (between 1995 and 2011) and pre-defined search keywords. Six main groups of innovative technologies were identified ('Personal Digital Assistant-', 'Mobile-phone-', 'Interactive computer-', 'Web-', 'Camera- and tape-recorder-' and 'Scan- and sensor-based' technologies). Compared with the conventional food records, Personal Digital Assistant and mobile phone devices seem to improve the recording through the possibility for 'real-time' recording at eating events, but their validity to estimate individual dietary intakes was low to moderate. In 24-hour dietary recalls, there is still limited knowledge regarding the accuracy of fully automated approaches; and methodological problems, such as the inaccuracy in self-reported portion sizes might be more critical than in interview-based applications. In contrast, measurement errors in innovative web-based and in conventional paper-based Food Frequency Questionnaires are most likely similar, suggesting that the underlying methodology is unchanged by the technology. Most of the new technologies in dietary assessment were seen to have overlapping methodological features with the conventional methods predominantly used for nutritional epidemiology. Their main potential to enhance dietary assessment is through more cost- and time-effective, less laborious ways of data collection and higher subject acceptance, though their integration in epidemiological studies would need additional considerations, such as the study objectives, the target population and the financial resources available. However, even in innovative technologies, the inherent individual bias related to self-reported dietary intake will not be resolved. More research is therefore cruc