The USDA Food and Nutrient Database for Dietary Studies (FNDDS), is a database of foods, nutrient values, and weights for food portions. Used to analyze data from the survey "What We Eat in America" (WWEIA), the dietary intake component of the National Health and Nutrition Examination Survey (NHANES). Based on nutrient values in the USDA National Nutrient Database for Standard Reference. Database is updated every two years, currently version 4.1.