Peter J. Havel is internationally renowned for multidisciplinary and ground-breaking research in understanding the metabolic and hormonal pathways involved in body weight regulation and in the pathophysiology of obesity and diabetes. His recent research investigates the endocrine, metabolic, and dietary factors that regulate the production of leptin and other hormones produced by fat cells that play critical roles in regulating food intake, energy expenditure, fuel metabolism, and body weight.
Currently a Research Associate Professor of Nutrition, Havel graduated from the University of Washington with a B.S. in Zoology (1988), then in 1994 earned both a doctorate in Veterinary Medicine and a Ph.D. in Endocrinology here at UCD. After teaching Endocrine and Gastrointestinal Physiology in the School of Veterinary Medicine for two years, he assumed a research faculty position in Nutrition in 1995. Initially focused on the neural control of pancreatic hormone secretion, Havel has extended his research program into the field of body weight regulation and obesity. His laboratory has been investigating the role of molecular and biochemical mechanisms in regulating leptin in vitro and in animals, including rodents and non-human primates, and in clinical studies of humans.
Dr. Havel’s laboratory demonstrated that leptin production in fat cells is regulated by glucose metabolism, that higher leptin levels in women compared to men cannot be solely explained by a higher proportion of body fat, and that leptin levels respond differently during periods of energy restriction in men and women. These findings suggest a major gender difference in endocrine regulation of metabolism.
After in vitro and rodent studies suggested that insulated-mediated glucose metabolism has a role in regulating leptin production, his team began investigating the effects of human diet on leptin. His laboratory demonstrated that consuming high fat meals reduces leptin concentrations in humans, providing a potential explanation of why high fat diets can cause obesity. Speculating that increased consumption of fructose in the United States might contribute to obesity, his recent research has shown that fructose does not stimulate the release of insulin or increase circulating leptin levels. Results of a study comparing the effects of consuming beverages sweetened with glucose or fructose suggest that consumption of high fructose diets may lead to increased energy intake, obesity, and increases of triglycerides. If continuing research definitively links fructose consumption to obesity and type 2 diabetes, it could have a major impact on dietary recommendations and dietary control of obesity, diabetes, and cardiovascular disease.
Colleagues admire Havel’s innovative and productive lab and his prodigious publication record. In the past five years he has published 16 book chapters and review articles and 45 peer reviewed articles, in major journals such as American Journal of Physiology, Endocrinology, American Journal of Clinical Nutrition, and Diabetes. The ground-breaking significance of his work is reflected by more than 2000 citations in the scientific literature, a report of invention and a patent application for a method of increasing the production of leptin. Dr. Havel has supported this research almost exclusively by obtaining extramural funding from sources such as NIH, USDA, and the American Diabetes Association.