Dr. Christopher Still, DO, is a professor of medicine at the Geisinger Commonwealth School of Medicine. He is also the medical director of the Center for Nutrition and Weight Management within the Geisinger Obesity Institute. Dr. Still has studied the developments in nutrition, metabolic syndrome, and obesity for nearly three decades. His work has included: research into genetic markers for obesity; nonalcoholic steatohepatitis; diabetes; the metabolic differences among men with obesity, formerly with obesity, and average-weight men; surgical options for patients with severe obesity; and leptin-level determination among older adult women with obesity.