Investigator image not available
Director of the Geisinger Obesity Institute
Medical Director, Center for Nutrition and Weight Management

Department of Gastroenterology/Nutrition
100 North Academy Avenue
Danville, PA 17822 
Phone: 570-271-6439
Fax: 570-271-5021

Geisinger Obesity Institute
100 North Academy Avenue
Danville, PA 17822 
Phone: 570-271-6439
Fax: 570-271-5021

Research Interests

Dr. Still has been studying developments in nutrition, metabolic syndrome, and obesity for nearly two decades. His work has included research into genetic markers for obesity, NASH 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 women. He serves as principal investigator on a rural elderly nutrition and aging study of some 22,000 individuals.

He is the author of the book chapter on obesity in Conn's Current Therapy, 1999, 2007 and 2008 editions and the co-author of several other textbook chapters. He has also published in several journals, including Archives of Surgery, Current Gastroenterology Reports, Journal of Clinical Gastroenterology, and Surgery for Obesity and Related Disorders. He has lectured on such subjects as vitamin and mineral metabolism; diet, nutrition, and exercise; obesity through the life cycle; and peri-operative medical and nutritional management of the bariatric surgery patient.

Dr. Still is certified by the American Board of Internal Medicine, the American Board of Physician Nutrition Specialists, and the American College of Nutrition, among others. He belongs to several professional societies, including The Obesity Society, American Society of Metabolic and Bariatric Surgery 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 serves on the board of directors for the Surgical Review Corporation, The Obesity Action Coalition and the American Board of Physician Nutrition Specialists as well as others editorial boards. He and his program have been featured on CNN, National Public Radio, ABC News, The Discovery Health Channel and several local affiliates.

Recent Publications 

  • Ford DW, Jensen G, Still C, Wood GC, Mitchell D, Erickson P, Bailey R, Smiciklas-Wright H, Coffman D, Hartman TJ. (2014). The associations between diet quality, body mass index (BMI) and health and activity limitation index (HAlex) in the Geisinger Rural Aging Study (GRAS) . J Nutr Health and Aging , 18:167-70 .
  • Ford DW, Hartman TJ, Still C, Wood C, Mitchell DM, Erickson P, Bailey R, Smicikas-Wright H, Coffman DL, Jensen GL. (2014). Body mass index, poor diet quality and health related quality of life are associated with mortality in rural older adults. Journal of Nutrition in Gerontology and Geriatrics , 33(1):23-34 .
  • Still CD, Wood GC, Strodel W, Petrick A, Gabrielsen J, Ibele A, Irving B, Seiler J, Benotti P, Celaya MP, Blackstone R, Gerhard GS, Argyropoulos G . (2014. Jan.). Preoperative prediction of type 2 diabetes remission following RYGB surgery. The Lancet Diab & Endocr , 2(1):38-45.
  • Still CD, Wood GC, Chu X, Manney C, Strodel W, Petrick A, Gabrielsen J, Mirshahi T, Argyropoulos G, Seiler J, Yung M, Benotti P, Gerhard GS. (2014, Mar). Clinical factors associated with weight loss outcomes after Roux-en-Y gastric bypass surgery. Obesity , 22(3):888-94.
  • Gerhard GS, Chu X, Wood GC, Gerhard GM, Benotti P, Petrick AT, Gabrielsen J, Strodel WE, Still CD, Argyropoulos G. (2013). Next-generation sequence analysis of genes associated with obesity and nonalcoholic fatty liver disease-related cirrhosis in extreme obesity. Hum Hered , 75(2-4):144-51.


M.S., Columbia University Institute of Human Nutrition, 1986
D.O., Philadelphia College of Osteopathic Medicine, 1991
Internship, University of Buffalo, 1992
Residency, Fellowship Geisinger Medical Center, 1995-1996