The USDA publishes a nutrition database once a year. It's an interesting data set to explore, so I decided to create and publish several different types of view. These are all very basic. This workbook was mostly an exercise of creating a simple, guided experience for exploring the data, as opposed to making a case for or against certain types of nutrients.
The website to get started is http://www.ars.usda.gov/services/docs.htm?docid=8964.