Obesity Research Institute

The Geisinger Obesity Institute (GOI) seeks to enhance the quality and quantity of research related to obesity within the Geisinger Health System by providing a system-wide focal point for all researchers, clinicians and trainees interested in the issues related to obesity and by establishing the necessary resources to support obesity research in epidemiology, clinical research and translational/molecular research.


Christopher D Still, DO


Contact us

Obesity Institute
Geisinger Health System

100 N. Academy Ave.
Danville, PA 17822-2111

Call us at 570-271-6709
Fax: 570-271-5201

Initiatives & Projects

Predictors of Weight Loss

Gastric bypass surgery is an effective therapy for extreme obesity. Although the safety and potential efficacy of this procedure is well established, some patients may regain variable amounts of weight after a short period of rapid weight loss and remain extremely obese.

There are many phenotypic, genetic, environmental and behavioral reasons for this. Our studies attempt to identify pre-operative factors associated with weight loss outcomes after surgery.

Resolution of Co-morbidities

Morbid obesity is often associated with many different co-morbidities such as type 2 diabetes, hypertension, cardiovascular disease, stroke, sleep apnea and gallbladder disease. Research has shown that many of these co-morbidities can be reduced through bariatric surgery. For example, evidence suggests that the rearrangement of the intestines during bariatric surgery and the change in physiological mechanisms can possibly result in remission of type 2 diabetes within days of surgery. Our research aims to better understand these mechanisms to help better predict post-surgery outcomes.

Maternal and Pediatric Obesity

National and state estimates regarding the health impact of maternal and pediatric obesity are staggering. Maternal and pediatric obesity prevention and treatment research in Geisinger Health System involves the Janet Weis Children's Hospital, Pediatrics, Women's Health, Maternal and Fetal Medicine, Center for Clinical Innovations, Obesity Institute, eHealth, Strategic Industry Partnerships, Genomic Medicine Institute, Environmental Health Institute and Center for Health Research.

Our research focuses on the genetic, molecular, social and behavioral contributors to obesity, and supports our work with community and public health partners, schools and parents to prevent and reduce childhood obesity with a strong focus on the first 1000 days of life beginning with conception. We are re-engineering care to improve screening, tailoring preventive counseling, and using systems design to direct families to multi-disciplinary, treatment programs when indicated.  We are training primary care providers and support staff to use motivational interviewing skills, utilizing tele-health, apps, and electronic health records, and coordinating care between clinics and community agencies and schools to help families identify and act on solutions that make healthy, active choices easier. 

Genetic Contributors to Obesity

Body weight is influenced by both genes and environment. Diet, exercise, where one lives and many other environmental factors interact with genes to predispose people to obesity. The Human Genome Project has now allowed scientists to identify obesity genes. Our goal is to discover and validate genetic factors that can cause or influence obesity.

Our research focuses on not only the genetic factors that may affect the onset of obesity, including intergenerational transmission, but also genetic variations associated with better outcomes after bariatric surgery. We hope our research will provide information to improve individualized patient care both for the current obese population and for future generations..

Non-Alcoholic Fatty Liver Disease (NAFLD)

This study directly addresses two important health problems, obesity and fatty liver disease, called non-alcoholic fatty liver disease (NAFLD). Over 70 percent of the adult population in the U.S. are overweight or obese as are 20-25 percent of children and adolescents. Obesity may soon overtake smoking as the leading cause of death in the U.S. About 20-30 percent of obese adults in the U.S. have excess fat accumulation in the liver. About 10 percent of these individuals (2-3 percent of all adults) are estimated to meet current diagnostic criteria for NAFLD. NAFLD can progress to cirrhosis in up to one third of these cases. The incidence of NAFLD increases with an increase in body mass index (BMI). BMI increases in proportion to weight increase. Although NAFLD is the second cause of liver transplantation, weight loss has been shown to improve NAFLD.

Obesity, Bariatric Surgery and Cardiovascular Disease

Obesity is associated with an increased risk for all-cause mortality.  Mortality risk related to obesity is largely associated with cancer and cardiovascular disease.   Mechanisms known to contribute to the strong association between obesity and cardiovascular disease include the indirect effects of obesity on known cardiovascular risk factors including hypertension, dyslipidemias and type 2 diabetes and the direct adverse effects of obesity on the homeostasis of the endothelium.  Additional mechanisms include the adverse effects of obesity on cardiac structure and function.  

The Geisinger Obesity Institute is uniquely positioned to explore the long-term benefits of surgical weight loss and cardiovascular outcomes as a result of its robust clinical bariatric surgery registry, established in 2004 and continuously fed by the electronic health record. A large cohort of surgical patients with follow-up beyond seven years has allowed comparison of long term cardiovascular outcomes with a tightly matched cohort of non-operated control patients with severe obesity. The outcome benefits of bariatric surgery shown in this cohort coupled with the prospective tissue biobanking in conjunction with obesity surgery afford opportunities for translational studies designed to uncover atherogenic-protective mechanisms.

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