Book excerpt: Federal guidance on nutrition and diet is intended to reflect the state of the science and deliver the most reliable recommendations possible according to the best available evidence. This guidance, updated and presented every 5 years in the Dietary Guidelines for Americans (DGA), serves as the basis for all federal nutrition policies and nutrition assistance programs, as well as nutrition education programs. Despite the use of the guidelines over the past 30 years, recent challenges prompted Congress to question the process by which food and nutrition guidance is developed. This report assesses the process used to develop the guidelines; it does not evaluate the substance or use of the guidelines. As part of an overall, comprehensive review of the process to update the DGA, this first report seeks to discover how the advisory committee selection process can be improved to provide more transparency, eliminate bias, and include committee members with a range of viewpoints for the purpose of informing the 2020 cycle.