The western world faces a very significant obesity epidemic. In Australia, two-thirds of our population or 12.5 million are either overweight or obese and as a consequence may experience many medical sequelae including development of the metabolic syndrome, type 2 diabetes, cardiovascular disease, cerebrovascular disease, osteoarthritis and depression, contributing significantly to our health burden. In the first part of this series, we were joined by Joseph Proietto, Professor Emeritus at the University of Melbourne, the Department of Medicine at Austin Health and an endocrinologist specialising in diabetes and obesity to discuss why we become obese. Professor Proietto joins us again to guide us through a strategy of how to treat and manage obesity and direct our patients toward a healthy body mass index (BMI).