Dr. Klein is the William H. Danforth Professor of Medicine, Director of the Center for Human Nutrition, Director of the Center for Applied Research Sciences, Chief of the Division of Geriatrics and Nutritional Sciences, and Director of the Weight Management Program at Washington University School of Medicine in St. Louis, Missouri. Dr. Klein received an MD degree from Temple University Medical School, and an MS Degree in Nutritional Biochemistry and Metabolism from the Massachusetts Institute of Technology. He completed residency training in Internal Medicine and a Clinical Nutrition fellowship at Boston University Hospital, a Nutrition and Metabolism Research fellowship at Harvard Medical School, and a Gastroenterology fellowship at The Mt. Sinai Medical Center in New York. He is board certified in Internal Medicine, Gastroenterology, and Nutrition.
Dr. Klein is past-president of the North American Association for the Study of Obesity and the American Society for Clinical Nutrition, and inaugural chair of the Integrative Physiology of Obesity and Diabetes NIH study section. He was elected to the American Society for Clinical Investigation in 1996 and to the American Association of Physicians in 2008. Dr. Klein has had consistent R01 funding from the NIH since 1990, and has published more than 450 papers in nutrition, metabolism, and obesity. He has received numerous awards for his research, including the American Gastroenterological Association (AGA) Miles and Shirley Fiterman Foundation Award in Nutrition, the AGA Masters Award for Outstanding Achievement in Basic or Clinical Research in Digestive Sciences, the AGA Obesity, Metabolism & Nutrition Research Mentor Award, the Academy of Science-St. Louis Award for Outstanding Achievement in Science, the American Society for Nutrition Robert H. Herman Award, the American Society for Parenteral and Enteral Nutrition George Blackburn Research Mentorship Award, and The Obesity Society TOPS Research Achievement Award, George A. Bray Founders Award, and the George L. Blackburn Award for Excellence in Obesity Medicine, the American Society for Parenteral and Enteral Nutrition George Blackburn Research Mentorship Award, and the Gerald M. Reaven Distinguished Leader in Insulin Resistance Award. Dr. Klein’s research activities are focused on understanding the mechanisms responsible for metabolic dysfunction associated with obesity, particularly nonalcoholic fatty liver disease, and the therapeutic effects of weight loss. Dr. Klein is also committed to training young investigators and clinicians in nutrition and obesity and has provided mentorship to 48 trainees in clinical and translational metabolic research.