Frequently Asked Questions


Do you have intake data for individual foods?

The GDD model determines and characterizes foods by group (e.g., "fruits" rather than "apples," "pears," etc.). Doing so maximizes the validity and accuracy of our prediction model and better facilitates comparisons of diet across countries.

Individual food intake data are also available on the GDD site, including:

  1. Original survey microdata:
    • Through correspondence with our private data owners, we have established data-sharing agreements to publicly host their individual-level, non-modeled “microdata” on the GDD site. These microdata often contain dietary intake data for individual foods, which can vary widely between surveys. These microdata will be made available starting in Summer 2020.
  2. Newly-standardized microdata using FoodEx2:
    • For information regarding GDD efforts—coordinated and harmonized with GIFT and EFSA—to standardize and disseminate intake data for individual foods across surveys via FoodEx2, go to this page.

Can I access the primary survey data you have?

A key aim of the GDD is to become an archive of all the surveys which serve as our model inputs. Such a functionality will be helpful in connecting researchers with one another and with important data on the populations they study. However, this functionality relies on significant collaboration from the original data owners. We have collected and continue to actively pursue signed data-sharing agreements (DSAs) with survey owners to ensure the safe and responsible sharing of their raw data (microdata).

GDD site users will be able to access general survey information about all surveys used for GDD input data, with or without DSAs, via an interactive global data availability map. This map is currently being constructed and will be updated on a rolling basis to reflect updates in DSA status. Users will be able to filter this map display by survey characteristics (assessment method, subject age range, representativeness, etc.) to isolate countries and surveys of interest. Surveys for which a DSA is in place will have an associated, freely-available dataset that users can download or request (when applicable). For publicly available datasets, links to the site from which the dataset originates will be listed in lieu of data files, which generally cannot be directly shared based on the original data-sharing requirements of the owners.  

We anticipate this process will be completed as scheduled by June 2020.

Do you estimate distributions or adequacy of nutrient intake for populations?

Currently, the GDD prediction model is designed to estimate mean dietary intake across subgroups by country-year, synthesizing information from various types of surveys. We also plan to expand our work to estimate the usual intake distribution—that is, to estimate usual dietary intake from just the means and standard deviations of intake provided to us by contributing members. Work on this aspect is ongoing.

Can I contribute my survey data to GDD?

We are always open to collaboration and strongly believe in fostering an environment for open data sharing. However, to allow completion of the findings, the incorporation of surveys into the GDD 2018 modeling phase has closed. Any additional surveys which may be identified or shared will be reserved for a future round of funding and efforts (e.g., GDD 2020).