Task 1: Key Concepts About the Food and Nutrient Database for Dietary Studies (FNDDS)

The FNDDS is a database of foods, their nutrient values, and their weights for typical food portions.  It consists of three components, including the food descriptions component, the food portions and weights component, and the nutrients component.  These three components are used to process and analyze NHANES dietary recall data.


Food Description Component

The Food Descriptions Component contains descriptions for about 13,000 foods.  Every food in the database has an 8-digit code associated with it.  These codes are the link between the FNDDS and the recall data.  These codes are used to identify foods in each of the three FNDDS components. 

Each food description has two versions—a complete, 200 character version and an abbreviated, 60-character version, which is written in capital letters.  Here is an example of a food description for food code 27345410.


Example Food Description - 27345410

Complete description: Chicken or turkey, rice, and vegetables (including carrots, broccoli, and/or dark- green leafy), cream sauce, white sauce,  or mushroom soup-based sauce (mixture)
Abbreviated description



When dietary recall data are coded and processed, the Food Descriptions Component is used to convert the foods reported by participants to the appropriate USDA food code. 


Food Portions and Weights Component

The Food Portions and Weights Component contains the weights, in grams, for common portions of each food in the FNDDS.  The FNDDS contains about 30,000 food portion weights.  When dietary intake data are coded and processed, this component is used to convert the amount of each food reported by the participant into gram weights.  Only the gram weights are included in the Individual Foods File.  The gram weights are used, along with the FNDDS nutrient values, to calculate the nutrient content of each food amount.


Nutrients Component

The Nutrients Component includes values for the amount of food energy and nutrients/food components contained in 100 grams of each food in the database.  The FNDDS nutrient values are used to calculate the nutrient amounts provided by each food reported on the dietary recalls.   


close window icon Close Window to return to module page.