was filed with Congress on June 1, 2016. This process ensures independent review in an open public manner, with opportunities for public participation. Committee Meetings The Committee held five public meetings over the course of 16 months. Meetings were held in July and October 2016, and March, July, and October 2017. The members met in person on the campus of the National Institutes of Health in Bethesda, Maryland, for each meeting. All meetings were publicly available live by videocast. In addition, the public was invited to attend the Committee’s first two meetings in person. All meetings were announced through a Federal Register notice. Meeting summaries, presentations, archived. Public Comments Oral comments from the public were presented at the second public meeting, and written comments were accepted throughout the tenure of the Committee. Written comments were shared with the Part B. Introduction 2018 Physical Activity Guidelines Advisory Committee Scientific Report B-5 Committee members as they were received. These comments are available for review at https://health.gov/paguidelines. The public comments process is described in Part H. Appendix 4. Public Comments. Committee Organization and Work Process During its first public meeting, the Committee decided that the work of reviewing the science would be best achieved by establishing subcommittees, each of which would review and interpret the literature for specific health outcomes and/or populations and summarize their findings as a chapter in the report. The Subcommittees, composed of Committee members and consultants, communicated by email and conference calls and met during public Committee meetings. Each Subcommittee was responsible for presenting to the full Committee its literature review process, grade and conclusion statement for each question, and research recommendations. During the public meetings, the Subcommittees responded to questions and made changes as indicated. The conclusions in this report represent the consensus of the entire Committee. The Committee formed nine subcommittees: Aging, Brain Health, Cancer – Primary Prevention, Cardiometabolic Health and Prevention of Weight Gain, Exposure, Individuals with Chronic Conditions, Promotion of Physical Activity, Sedentary Behavior, and Youth. After its first public meeting, the Committee formed three Work Groups to consider additional topics: Physical Fitness, Youth to Adult Transition, and Pregnancy and Postpartum. The Subcommittee and Work Group organization are detailed in Part H. Appendix 2. PAGAC Subcommittee and Work Group Assignments. Each Committee member served on at least two Subcommittees, with the exception of the Co-Chairs, one of whom was a Subcommittee chair. The other Co-Chair participated in all of the other Subcommittees and Work Groups. To assist in the review process, Subcommittee chairs identified consultants to fill knowledge gaps in one or more specific areas (see consultant list in Membership List). Consultants participated in Subcommittee discussions and decisions, but were not considered Committee members. Similar to Committee members, they completed ethics training and went through a federal review and clearance process. In addition, outside experts (see list in Membership List) provided information or a presentation to Subcommittees or Work Groups on a specific topic or question at one meeting. A Designated Federal Officer (DFO) and Alternate DFO from the Office of Disease Prevention and Health Promotion (ODPHP) supported the Committee members. ODPHP served as the administrative lead for Part B. Introduction 2018 Physical Activity Guidelines Advisory Committee Scientific Report B-6 this project. The DFO and Alternate DFO also served as two of the seven Co-Executive Secretaries, who represented the various agencies responsible for federal physical activity policy and programs. These agencies include ODPHP, the Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH), and the President’s Council on Fitness, Sports & Nutrition (PCFSN). Each Subcommittee was supported by a federal staff liaison trained in the Federal Advisory Committee Act management and a systematic review liaison from the literature review team. Approaches to Reviewing the Evidence The Committee used the state-of-the-art methodology—systematic reviews—to address its 38 research questions and 104 subquestions. These reviews are publicly available on https://health.gov/paguidelines/second-edition/report/supplementary-material.aspx. Part E. Systematic Review Literature Search Methodology of this report details the process used by the Committee to evaluate the scientific evidence. This section also describes the grading rubric the Committee used to grade the level of evidence available to answer its questions. Each Subcommittee drafted a chapter that summarizes and synthesizes the results of its review and includes the evidence grades and conclusion statements for each question (see Part F. The Science Base). Research recommendations to address gaps that could advance knowledge related to the question posed and inform future federal physical activity guidance, as well as other policies and programs, are included at the end of each chapter and in