After decades of increases in the obesity rate among U.S. adults and children, the rate recently has dropped among some populations, particularly young children. What are the factors responsible for these changes? How can promising trends be accelerated? What else needs to be known to end the epidemic of obesity in the United States? To examine these and other pressing questions, the Roundtable on Obesity Solutions, of the National Academies of Sciences, Engineering, and Medicine, held a workshop in September 2016. The workshop brought together leaders from business, early care and education, government, health care, and philanthropy to discuss the most promising approaches for the future of obesity prevention and treatment. This publication summarizes the presentations and discussions from the workshop.