Nutrition Evidence Library

USDA’s Nutrition Evidence Library (NEL) specializes in conducting systematic reviews to inform nutrition policy and programs. The Library evaluates, synthesizes, and grades research using rigorous and transparent methodology to define the state of food and nutrition-related science. NEL provides ongoing support to the Dietary Guidelines Advisory Committee’s scientific review process for developing recommendations for the Dietary Guidelines for Americans. In the future, NEL will serve as a key resource for making food and nutrition research accessible to all Americans
NEL Process 
  • Recruit expert workgroup
  • Formulate evidence analysis questions
  • Conduct literature review for each question
  • Extract evidence and critically appraise each study
  • Synthesize the evidence
  • Develop and grade a conclusion statement