Obesity, a condition of excess body fat, is one of the most complex problems facing health systems. Lifestyle management programs that combine diet, physical activity, and intensive behavioral therapy have been shown by research to support a degree of weight loss that produces health benefits (i.e., at least a 3-5% initial body weight). However, it has been difficult for research-developed programs to be delivered in typical practice to have a meaningful impact. Integrated research-practice partnerships that involve the coming together of academic researchers, health system administrators, and program delivery staff may help overcome this gap, especially during this transformational time in the healthcare sector. This dissertation aimed to develop an understanding of how using the integrated research-practice approach would facilitate and sustain evidence-based lifestyle management strategies across a health system to treat obesity among patients and employees. An integrated research-practice partnership with Carilion Clinic, a health system in western Virginia, served as an example for the study. From 2013-2016, the Carilion Clinic integrated research-practice partnership conducted a series of trials testing different strategies for delivering weight loss and weight loss maintenance support. An evaluation guided by the RE-AIM (Reach, Effectiveness, Adoption, Implementation, and Maintenance) framework was conducted to describe implementation processes and outcomes for each strategy. Lessons learned from the evaluation support the value of the integrated-research practice partnership approach as a solution for overcoming gaps in obesity care. A shared priority perspective between research and practice was identified as the powerful process for supporting facilitation and sustainability of strategies. In addition, findings from the evaluation produced evidence to inform the future development of a system for Carilion Clinic to help patients and employees lose weight and keep it off through lifestyle management. / Ph. D.