The American Journal of Preventive Medicine published a special theme issue highlighting discussions and recommendations from the July 2013 Built Environment Assessment Training (BEAT) Institute meeting. The BEAT Institute was developed to train investigators to use observational and self-reported measures of nutrition and activity environments, integrating the disciplines of nutrition, physical activity, obesity prevention, urban planning, and transportation. The 2013 meeting aimed to set an agenda for the future of the field and identify concrete products to be developed and disseminated. Expert participants discussed priorities, gaps, and promising opportunities to advance the science and practice of measuring obesity-related built environments. This themed collection from participants of the 2013 BEAT meeting takes stock of the progress to date in built environment assessment and interventions for obesity prevention, and looks ahead at important areas for future research, intervention development, and training.