This report explores the structure and function of the U.S. nutrition research system, with an emphasis on trends in Federal support. It describes how nutrition research is used, especially for nutrition education and communication, but also for regulation and food assistance. The report uses the Human Nutrition Research Information Management database maintained by the National Institutes of Health to analyze longterm trends. Federal investments in nutrition research grew from 1985 to 2009 in real terms, but the portfolio of research changed. Over time, the share of nutrition research support by the U.S. Department of Health and Human Services increased while support by the U.S. Department of Agriculture decreased. This shift changed how research topics were selected and funded within the Federal portfolio. More research is funded through competitive grants than through intramural or formula funding, and a broader set of academic institutions now participates in nutrition research.