"Treasure Your Exceptions"-Studying Human Extreme Phenotypes to Illuminate Metabolic Health and Disease: The 2019 Banting Medal for Scientific Achievement Lecture.

The study of humans with genetic mutations which lead to a substantial disturbance of physiological processes has made a contribution to biomedical science that is disproportionate to the rarity of affected individuals. In this lecture, I discuss examples of where such studies have helped to illuminate two areas of human metabolism. First, the control of insulin sensitivity and its disruption in states of insulin resistance and second, the regulation of energy balance and its disturbances in obesity.