Jason Block is the Associate Director and an Assistant Professor in the Obesity Prevention Program of the Department of Population Medicine at Harvard Medical School/Harvard Pilgrim Health Care Institute. He completed a primary care internal medicine residency and chief residency at Brigham and Women’s Hospital and was a Robert Wood Johnson Foundation Health and Society Scholar at the Harvard School of Public Health and a General Internal Medicine Fellow at Brigham and Women’s. He is a practicing primary care physician at Brigham and Women’s Hospital, where he sees his own panel of patients in an urban hospital-based clinic, supervises residents in their continuity clinic practice, and sees patients at a medical weight loss clinic. Dr. Block’s primary research interests are the evaluation of governmental and institutional policies intended to change dietary behaviors and novel interventions to treat or prevent obesity or weight gain. Most of his research involves use of large data sources, including retail transaction data and electronic health records. He previously served as a Senior Advisor to the Acting Assistant Secretary for Health at the US Department of Health and Human Services.