Christopher Doubet Still, DO, FACP, FTOSChristopher D. Still, DO, FACP, FTOS, is Professor of Medicine at the Geisinger Commonwealth School of Medicine. He is also the Medical Director, Center for Nutrition and Weight Management; Director, Geisinger Obesity Institute; Geisinger Health System, Danville, Pennsylvania. Dr. Still received a Master of Science degree from Columbia University Institute of Human Nutrition in New York City and his osteopathic medical degree from The Philadelphia College of Osteopathic Medicine, Pennsylvania. He completed his internship at the University of Buffalo at Sisters of Charity Hospital, New York, followed by a residency in internal medicine and a subsequent fellowship in clinical nutrition and obesity treatment at Geisinger Medical Center.Dr. Still has been studying developments in nutrition, metabolic syndrome, and obesity for nearly 3 decades. His work has included research into genetic markers for obesity; nonalcoholic steatohepatitis, and diabetes; the metabolic differences among obese, formerly obese, and normal-weight men; surgical options for severely obese persons; and leptin-level determination among elderly obese womenDr. Still is certified by the American Board of Internal Medicine, American Board of Obesity Medicine, American Board of Physician Nutrition Specialists, and American College of Nutrition. He is a member of several professional societies, including The Obesity Society, American Society for Metabolic and Bariatric Surgery (ASMBS), and the American Society of Parenteral and Enteral Nutrition. He is a fellow of the American College of Physicians and the American College of Nutrition. He served on the board of directors for the Obesity Action Coalition and is the past president of the National Board of Physician Nutrition Specialists.