DIET@NET: Best practice guidelines for dietary assessment in health research

Background: Dietary assessment is complex and strategies to select the most appropriate dietary assessment tool (DAT) in epidemiological research are needed. The Dietary Assessment Tools Network (DIET@NET) aimed to establish expert consensus on Best Practice Guidelines (BPG) for dietary assessment using self-report. Methods: The BPG were developed using the Delphi technique. Two Delphi rounds were conducted. 131 experts were invited, of these 65 accepted, with 48 completing Delphi round I and 51 completing Delphi round II. In all, a total of 57 experts from North America, Europe, Asia, and Australia commented on the 47 suggested guidelines. Results: 43 guidelines were generated, grouped into 4 stages: Stage I. Define what is to be measured in terms of dietary intake (what? who? and when?); Stage II. Investigate different types of DAT; Stage III. Evaluate existing tools to select the most appropriate DAT by evaluating published validation studies; Stage IV. Think through the implementation of the chosen DAT and consider sources of potential biases. Conclusions: The Delphi technique consolidated expert views on best practice in assessing dietary intake. The BPG provide a valuable guide for health researchers to choose the most appropriate dietary assessment method for their studies, these guidelines will be accessible through the Nutritools website, www.nutritools.org.