The Departments of Agriculture and of Health and Human Services established the 2020 Dietary Guidelines Advisory Committee for the single, time-limited task of examining the evidence on specific nutrition and public health topics and providing independent, science based advice to the Federal government as the Departments develop the next edition of the Dietary Guidelines for Americans. The 2020 Committee used 3 approaches to examine the evidence: data analysis, food pattern modeling, and NESR systematic reviews. Each of these approaches has its own rigorous, protocol-driven methodology, and played a unique, complementary role in examining the science.