FoodEx2 Data Harmonization

We’re working with EFSA and FAO/WHO GIFT to bring FoodEx2, the most detailed and intricate food classification system in the world, to dietary datasets in GDD.

 

What is FoodEx2?

When data on food intake is collected using dietary surveys, there can be lots of variation—both in the way participants report their diet and the way researchers classify it. This variation poses a substantial challenge in comparing datasets across groups, and particularly across countries. To address this challenge, the European Food Safety Authority (EFSA) has developed a sophisticated and easy-to-use food classification and description system, FoodEx2. The application of FoodEx2 to dietary surveys ensures that individual foods are uniformly classified across surveys, no matter how different, from around the world. Now, GDD is mapping individual-level dietary data collected using 24-hour recalls or food records using FoodEx2 to enhance the transparency and availability of harmonized dietary data to the global nutrition community.

The image below provides a glimpse at the incredible granularity of the FoodEx2 mapping tool. In the example below, the minimum required level for FoodEx2 coding would be that in red, “rye only bread and rolls.” There are currently about 4,500 terms available in the EFSA Catalogue Browser!

FoodEx2 example

 

It is with critical tools like FoodEx2 that GDD will be able to more precisely characterize global dietary intakes and inform nutrition interventions and policies to address diet-related disease burdens worldwide.

How Our Partnerships Play a Role

In 2016, the Friedman School of Nutrition Science and Policy began collaborating with WHO/FAO GIFT, a fellow Gates Foundation-funded initiative, to develop methods and approaches for harmonizing individual-level dietary data. Through this collaboration with WHO/FAO GIFT, we have developed common principles and supporting materials and tools to streamline harmonization. In 2018, a partnership was finalized with EFSA, the developer of FoodEx2, to select FoodEx2 as the official data harmonization tool of GDD and WHO/FAO GIFT.

Our Recent Progress and Our Upcoming Goals

Our efforts have included developing materials to identify and prioritize eligible surveys, contact survey owners to invite them to join this effort, train data owners to the FoodEx2 mapping tool, and provide and document financial support to our data owner collaborators.

As of 2019, we have contacted data owners of 135 surveys, including 8 which were introduced to GDD by GIFT and 41 by EFSA.

At this point, we have begun the FoodEx2 coding process for 38 of these surveys:

  • 12 will be harmonized by the respective data owners
  • 7 will be harmonized by GDD
  • 11 datasets have been FoodEx2 harmonized by EFSA
  • 8 datasets have been harmonized by GIFT

GDD is also working to harmonize large, nationally representative surveys. At this point, FoodEx2 harmonization has been completed for the Canadian Community Health Survey (CCHS) 2015 and is currently underway for NHANES 2015-2016.

GDD aims to harmonize 15 datasets by the end of 2019 and 45 datasets by the summer of 2020—and you can help.

If you have 24-hour recall or food record data that you would like to contribute, please contact gddmicrodata@tufts.edu. As a reminder: you have the option to map your survey’s food items using FoodEx2 yourself (with our guidance), or we can map them for you.