Jørn V. Sagen, M.D., Ph.D., is Head of department at the Hormone Laboratory, Haukeland University Hospital, and Professor at the Department of Clinical Science, University of Bergen.

He is a specialist in laboratory medicine (medical biochemistry). Dr. Sagen is also a chair member of the Norwegian Association for the Study of Obesity.

His current research interests include molecular mechanisms resulting in the development of obesity and diabetes mellitus. More specifically, he has focused on the development of brown adipocytes from mesenchymal stem cells, and the role of brown fat in regulating metabolism.