He is a professor of Social Medicine and of the Postgraduate Program in Epidemiology at the School of Medicine of the Federal University of Rio Grande do Sul, Porto Alegre, Brazil. He received his MD and an MPH at Johns Hopkins University, and trained in internal medicine at North Carolina Memorial Hospital. He then spent a brief period as a faculty member of the University of North Carolina Department of Epidemiology, where he continued in adjunct appointments through 2016.

Since arriving in Brazil in 1984, he has focused his attention on diabetes, on cardiovascular and other chronic diseases, and on primary care. He is a member of the Brazilian Academy of Science and a Research Fellow at the Brazilian National Council for Scientific and Technological Development (CNPq), and has been recognized by the Brazilian Ministry of Health for his work in support of chronic disease surveillance. He has also received the Michaela Modan Award of the American Diabetes Association, Epidemiology and Statistics Council. He is currently the President of the International Diabetes Epidemiology Group.

Over a period of years he focused his research interests on the role of the innate immune system in the underlying pathophysiology of diabetes and the metabolic syndrome. More recently he has worked to characterize the causes and burden of diabetes and other chronic diseases in Brazil and elsewhere, and on finding solutions for their prevention and adequate care within Brazil´s national health system. In this regard, much of his work has involved providing an evidence base for quality primary care and for dealing with chronic non-communicable diseases at all levels. He has authored over 300 articles in peer-reviewed journals and is the editor of a major Brazilian textbook in primary care. His publications have yielded 33000 citations and an H-index of 90 (Google Scholar).