Over the last six years, efforts to strengthen policies, systems, and environments to promote health and prevent obesity have become more robust and widespread. These efforts include updates to federal policies and programs, state regulations, local policies, and evidence-based guidance. The goal of the current research review is to provide the most up-to-date information on the impact of these changes in policies, systems, and environments aimed at promoting a healthy diet, increasing physical activity, and reducing screen time in young children in the ECE setting. The review finds that evidence has strengthened over the past five years that obesity prevention interventions involving multiple approaches, coupled with parental engagement, offer the most promising opportunities to improve dietary intake, increase physical activity, and reduce screen time, as well as to change anthropometric outcomes.