USDA's Nutrient Databank System – A tool for handling data from diverse sources

Abstract

Key features of USDA's Nutrient Databank System (NDBS) allow processing of food composition data from diverse sources, including USDA's National Food and Nutrient Analysis Program, the food industry, scientific literature, and food labels. The Nutrient Data Laboratory (NDL) designed the NDBS as a three-tiered (“Initial”, “Aggregation”, and “Compiled”) data management system to facilitate handling of data. Raw data and documentation (data source, sample description, sample handling, and analytical methods) are migrated into the Initial module. NDL scientists compare new data with old values and decide how to combine the initial data into aggregated data. In the Aggregation module, data can be grouped and weighted by parameters such as study, source, and market share. Depending on the type of data, various statistical algorithms are used to generate statistics, such as mean, standard error, number of data points, and error bounds. In the Compiled module, food names are finalized and common measures selected. Nutrient profiles are developed and missing nutrients/food components are imputed according to standardized scientific principles. A formulation application employing linear programming techniques, estimate, formulations for commercial foods and nutrient profiles based on the nutrient content of ingredients and target values derived from label information. A recipe application calculates nutrient profiles based on ingredients and their known proportions, allowing for the application of food yield and nutrient retention factors. The NDBS automatically documents how each value was derived and incorporates quality control checks at all levels. Prior to release, the completed nutrient profiles are reviewed by NDL scientists and, if approved, disseminated. The NDBS brings together a number of stand-alone modules and applications into one integrated system allowing the management of ∼7500 food items for up to 140 nutrients/food components. Data points and documentation are managed and maintained in one place, providing an “audit trail” for each data point. The NDBS contains algorithms to assign confidence codes using NDL's data quality evaluation system. The NDBS permits the annual release of reliable data for a comprehensive set of nutrients/food components for a wide variety of foods on NDL's Web site: http://www.ars.usda.gov/nutrientdata. Through these releases, NDL provides food composition data for researchers, diet and health professionals, and consumers, including the “What We Eat in America” component of the National Health and Nutrition Examination Survey (NHANES).