William Yancy MD, MPH

Dr. William Samuel Yancy Jr., MD, MHS, is an internal medicine physician, obesity medicine specialist, and clinical researcher at Duke Health. He is a professor of medicine and a recognized expert in medical weight management, with a career focused on improving health outcomes through sustainable lifestyle and dietary interventions.

Dr. Yancy specializes in the prevention and treatment of obesity and related chronic conditions. His clinical work emphasizes helping patients improve their quality of life and reduce disease risk through personalized, evidence-based weight management strategies. He practices in multidisciplinary programs such as the Duke Lifestyle and Weight Management Center, where care integrates medicine, nutrition, fitness, and behavioral support.

A leading physician-scientist, Dr. Yancy has conducted numerous clinical trials examining the safety and effectiveness of dietary approaches and medications for weight loss. His research has contributed significantly to the understanding of low-carbohydrate, low-glycemic, and reduced-calorie diets, as well as long-term adherence to lifestyle changes.

Dr. Yancy earned his medical degree from East Carolina University and completed his residency and chief residency in internal medicine at the University of Pittsburgh Medical Center. He later obtained a Master of Health Sciences from Duke University, where he also completed fellowship training in general internal medicine.

In addition to his clinical and research work, Dr. Yancy has held key leadership roles at Duke, including director of the Duke Diet and Fitness Center (now the Duke Lifestyle and Weight Management Center) and interim chief of the Division of General Internal Medicine. He is widely regarded as an authority on obesity management and the role of nutrition in chronic disease prevention.