This book promises a lot a the cover. It advertises itself as "A practical, accessible guide to understanding the diet myth and the secret to lasting weight loss." Andrew Jenkinson is a doctor and surgeon who specialises in bariatric (weight loss) surgery. In fact, his expertise is so highly regarded that he travels all over the world to consult on cases and pass on his knowledge to others in the medical field. In this book he spends the vast majority of it explaining the science (and some psychology) behind weight gain and loss. This is done in a very concise way and is backed up with numerous sources and at times with case studies of patients he has treated. Where there are differing views in medicine on a topic he explains why there are differing views and why he believes one holds more weight than the other. One of the stand out things in this book is that where the evidence isn't 100% he clearly states 'we believe' or 'we think', this is welcome break from the dogmatic approach often taken in other weight loss books.

Jenkinson starts off with a question along the lines of, "If weight gain is based purely on calories in vs calories out and we often eat an excess of calories above what we need, why don't we continue putting on weight forever?" In fact, if you look at the data collected, and weight gain = calories in - calories out, a great many of us who eat western diets should weigh in excess of 300kg, we don't, why is this? This question really sucked me in right from the start and Jenkinson looks at what causes obesity and why it really isn't simply a matter of willpower. Jenkinson then goes on to look at the role upbringing, genetics, environment, nutrition, food availability, etc all come into play.

The final section of the book is a general guide to how we should eat to maintain a health weight. Importantly he states that this is a slow process, he explains how crash diets work (or don't) and why we often end up putting more weight back on than we started with. He is also clear that our genetics pay a part in how we look and if you are naturally a 'bigger' person it is unlikely you can become a super skinny racing snake. This is a crucial message in my opinion. We can all change how we look and more importantly our health but there is no one 'perfect physical state' that will work for everyone. ( )