Professor Stephen O’Rahilly’s research has led to an increased understanding of the genetic causes of human obesity and insulin resistance. Using modern biochemical approaches and classical clinical observation in humans with profound metabolic disorders, O’Rahilly, from the Departments of Medicine and Clinical Biochemistry at the University of Cambridge, has shown that a person’s appetite and feeding behavior can be linked to specific genes. His work has challenged long-held dogmas and led to new treatment avenues. The full interview includes many more stories about how you can learn more from reading Chekhov than medical school and why he has stayed in Cambridge all these years.