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College of
Health Sciences


Director, Geisinger Obesity Institute
Medical Director, Center for Nutrition and Weight Management
Associate, Department of Gastroenterology and Nutrition

Professor of Medicine
Department of Clinical Science
Geisinger Commonwealth School of Medicine

Adjunct Clinical Assistant Professor of Nutrition
The Pennsylvania State University

Department of Gastroenterology/Nutrition
100 North Academy Avenue
Danville, PA 17822 

Geisinger Obesity Institute
100 North Academy Avenue
Danville, PA 17822 

Fax: 570-271-5021

Christopher D Still, DO, FACN, FACP, FTOS

Research Interests

Dr. Still has been studying developments in nutrition, metabolic syndrome, and obesity for nearly three decades.  His work has included research into genetic markers for obesity, NASH and diabetes; longitudinal assessment and outcomes of the bariatric surgery patient.  He also serves as principal investigator of the Geisinger rural elderly nutrition and aging study of some 22,000 individuals.

He has recently edited CRC Press 2014 Nutrition and Bariatric surgery as well as 2014 ASMBS Textbook of Bariatric Surgery, Volume1.  He has also published in multiple journals, including Obesity, PNAS, Lancet Endocrinology, Annals of Surgery, Gastroenterology, Journal of Clinical Gastroenterology, Surgery for Obesity and Related Disorders, Human Molecular Genetics, among others.   He has lectured on such subjects as vitamin and mineral metabolism; diet, nutrition, and exercise; obesity through the life cycle; and the peri-operative medical and nutritional management of the bariatric surgery patient.

Dr. Still is certified by the American Board of Internal Medicine, American Board of Obesity Medicine, the American Board of Physician Nutrition Specialists, and the American College of Nutrition.  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 served on the board of directors for The Obesity Action Coalition and is the past President of the National 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.  He was awarded the 2011 ASMBS’ Integrated Health Circle of Excellence Award.

Recent Publications 

  • Wood GC, Horowitz D, Still CD, Mirshahi T, Benotti P, Parikh M, Hirsch AG. Performance of the DiaRem Score for predicting diabetes remission in two health systems following bariatric surgery procedures in Hispanic and non-hispanic white patients. Obesity Surgery. Epub Jul 2017: 1-8. Doi: 10.1007/s11695-017-2799-y
  • Lent MR, Benotti PN, Mirshahi T, Gerhard GS, Strodel WE, Petrick AT, Gabrielsen JD, Rolston DD, Still CD, Hirsch AG, Zubair F, Cook A, Carey DJ, Wood GC: All-cause and specific-cause mortality risk after roux-en-y gastric bypass in patients with and without diabetes. Diabetes Care. Oct 2017; 40:1-7. Doi: 10.2337/dc17-0519
  • Wood GC, Chu X, Argyropolous G, Benotti P, Rolston D, Mirshahi T, Petrick A, Gabrielsen J, Carey D, DiStefano J, Still CD, Gerhard G: A multi-component classifier for nonalcoholic fatty liver disease (NAFLD) based on genomic, proteomic, and phenomic data domains. Scientific Reports; Mar 2017: 7, 43238; doi: 10.1038/srep43238
  • Fleming J, Wood GC, Seiler C, Cook A, Lent MR, Still CD, Benotti PN, Irving BA. Electronically Captured, patient-reported physical function: an important vital sign in obesity medicine. Obesity Science and Practice. September 2016: 1-8. DOI: 10.1002/osp4.67
  • Wang H, Hong CE, Lewis JP, Zhu Y, Wang X, Chu X, Backman J, Hu Z, Yang P, Still CD, Gerhard GS, Fu M. Effect of two lipoprotein (a)- Associated genetic variants on plasminogen levels and fibrinolysis. G3: Genes, Genomics, Genetics. 2016; 6(8): 1-28. DOI:10.1534/g3.116.034702.
  • Wood GC, Benotti PN, Lee CJ, Mirshahi T, Still CD, Gerhard GS, Lent MR: Evaluation of the Association Between Preoperative Clinical Factors and Long-Term Weight Loss After Roux-en-Y Gastric Bypass: JAMA Surgery, August 2016: 1-7. DOI: 10.1001/jamasurg.2016.2334


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
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