Development and application of a 2-step methodology to select a reference society providing Dietary Reference Values for national implementation

Objective: To describe and discuss a 2-step methodology developed to select a reference society that provides Dietary Reference Values (DRVs) for national implementation and to illustrate its application in Switzerland with one macronutrient and one micronutrient.
Design: During Step 1, we searched and compared DRVs and methodologies used to define DRVs from eight European societies for seven selected nutrients. We repeated this procedure during Step 2 for DRVs from two preselected societies for 44 nutrients.
Setting: The 2-step methodology applied here for Switzerland may be used in other countries
Participants: The research team commissioned six external experts from three linguistic regions of Switzerland, who provided their opinions through two online surveys, individual interviews, and a focus group.
Results: After Step 1, we excluded five societies because of old publication dates, irrelevant publication languages for Switzerland, difficulty in accessing documents, or because their DRVs were mainly based on another society. After Step 2, the two societies were qualified based on the analysis of the values and methodologies used. The need for free and easily accessible scientific background information favored the European Food Safety Authority (EFSA). We chose alternative societies for nine nutrients for the overall population or subgroups, and for elderly.
Conclusions: To manage heterogeneous and complex data from several societies, adopting a 2-step methodology including fewer nutrients and more societies during Step 1, and fewer societies but all nutrients in Step 2, was very helpful. With some exceptions, we selected EFSA as the main society to provide DRVs for Switzerland.