[Editor's Note: This API is no longer available. It has been replaced by the USDA FoodData Central API.]
Use the National Nutrient Database API to access USDA data on food nutrients. The REST API returns responses in JSON or XML and requires an API Key. Calls to the API are limited to 1,000 per hour, but the data is free and open to the public for use. Use the National Nutrient Database to generate nutrient reports, get lists of products by nutrient or food group, or search for a specific food product.