Abstract
By Michael L. Power and Jay Schulkin
Baltimore: Johns Hopkins University Press, 2009
408 pp, Price £22 (paperback)
ISBN: 978-0-8018-9262-2
In The Evolution of Obesity, Michael L Power and Jay Schulkin take us on an evolutionary journey in order to describe what has made ‘obesity’ what it is today. This is a timely publication as obesity is a topical and complex subject even though in recent years our understanding of it has vastly improved.
The authors focus on all aspects of metabolism, physiology and behaviour relevant to obesity. They explore the concept that the evolutionary and adaptive origins of human physiology predispose humans to obesity under the collective conditions of the modern-day lifestyle. The book can broadly be divided into three sections. In the first section (chapters 1–5), the authors focus on the prevalence of obesity, human evolution and food evolution and outline how present-day life has contributed to the epidemic. In the second section (chapters 6–8), they perform a very comprehensive review of current understanding about energy metabolism and the complex mechanisms though which the gut communicates with the brain in order to regulate appetite, satiety and energy homeostasis. Finally, in chapters 9–13, the focus is on the biology and functions of fat, and the numerous factors including different metabolism in men and women, cultural differences in food procurement, preparation and consumption, and the influence of sedentary lifestyles that influence fat (adipose tissue) distribution/deposition. I commend the authors for their bold approach and detailed discussion of the many physiological processes that contribute to obesity. In doing so, they have managed to systematically incorporate the latest scientific advances in the field of obesity to shed light on why our waistlines are expanding.
The audience of the Annals will find chapters 7 and 8 of great interest. Both of these chapters are written more like a journal review rather than book chapters. They cover the numerous peptides that are involved in the complex neuro-endocrine interplay between adipose tissue, gut and the brain in regulating appetite and satiety. In recent years, significant advances have been made in bariatric (weight loss) surgery and surgery is proving to be the most effective treatment option available for both significant and sustained weight loss. Furthermore, as the number of surgical procedures performed to combat the obesity epidemic is on the rise, much research focus has been on postsurgical adaptations and their effect on weight loss. This in turn has contributed greatly to our current understanding about the regulation of appetite and satiety in obese individuals. Thus, a chapter on bariatric surgery would have been a welcome addition. However, given that the overall scope of this book is the biology of fat, I can see why the authors excluded it. The other chapter of note for readers of Annals is chapter 11. Here, we read why and how the adipose tissue functions as an endocrine organ amongst its other well-known functions. The plethora of bioactive molecules produced by the adipose tissue and the supporting literature cited by the authors leave readers with no doubts as to the endocrine status of the adipose tissue.
The Evolution of Obesity provides an excellent and comprehensive explanation for the increased incidence of obesity and its consequences. It is definitely one of the best books on the topic at present, providing as it does a well-balanced overview of the fundamental processes that govern obesity. I strongly recommend it as a very informative and easily read book; it is an important source of reference for clinicians, biochemists, dietitians and all those interested in the causes of the obesity epidemic and obesity-related metabolic diseases.