Professor Truby grauated from the University of Wales in the United Kingdom and received her PhD from the University of Melbourne. She worked as a Clinical Specialist Dieteician for seven years at the Royal Children's Hospital in Melbourne, and is currently the head of the Nutrition and Dietetics Department at Monash University in Melbourne and is also an honorary researcher with The University of Queensland.

Professor Truby leads the "Eat Smart" study at the Children's Nutrition Research Centre. This study examines the energy requirements in young people with obesity and how different diets on affect changes in body composition during weight loss. She is also working on other research studies in conjuntion with the Queensland Diabetes Centre, Pathways Clinical and Research Centre, Montrose Access and the Neuromuscular Disease Clinic.