Obesity: Epidemiology, Pathophysiology, and Prevention PDF

Preface

The spread of obesity has been declared a worldwide epidemic by the World Health Organization (WHO). In fact, a new term, globesity, has been coined to describe the recent upsurge of overweight and obesity throughout the world's population. How severe is the problem? According to WHO, worldwide obesity has more than doubled since 1980. In 2008, 1.5 billion adults, 20 years and older, were overweight [1]. Of these, more than 200 million men and 300 million women were obese. Sixty-five percent of the world's population live in countries where overweight and obesity kills more people than underweight [1]. Furthermore, nearly 43 million children under the age of five were overweight in 2010 [1].

To make matters worse, overweight and obesity in children are significant public health problems in the United States. It has been estimated that between 16% and 33% of children and adolescents are obese [2]. The number of adolescents who are overweight has tripled since 1980, and the prevalence of obesity among younger children has more than doubled [2]. According to the 1999–2002 National Health and Nutrition Examination Survey (NHANES), 16% of children aged between 6 and 19 years are overweight. Not only have the rates of overweight in children increased, but also the heaviest children in a recent NHANES were markedly heavier than those in previous surveys [2]. In addition to type 2 diabetes, obesity has also been linked to other broad-spectrum, degenerative diseases, including other metabolic disorders and certain forms of cancer. It has been reported that 80% of type 2 diabetes, 70% of cardiovascular diseases, and 42% of breast and colon cancers are related to obesity [3]. Obesity is the major factor behind 30% of gallbladder perturbations, leading to surgery, and 26% of incidences of high blood pressure.

This unfortunate outcome has generated an unlimited array of weight loss strategies. Products and programs that induce rapid weight loss and disturb metabolic homeostasis dominate the focus of marketers and consumers alike; however, rapid weight loss is potentially unhealthy and frequently induces undesirable rebound weight gain consequences. In addition, many antiobesity pharmaceuticals are accompanied by adverse reactions, making the cure worse than the disorder itself; thus, it is very important to develop a strategic therapeutic intervention using safe, novel, and natural supplements supported by credible research. This book, intended for practicing medical professionals, clinical nutritionists, dieticians, and researchers, addresses many issues relevant to obesity: the molecular mechanism and pathophysiology leading to obesity and metabolic disorders, the safety of obesity drugs, drug development strategies, the influences of physical activity and nutrition, and the benefits of research-supported nutraceutical supplements.

The 63 chapters in this book have been written by experts in their respective fields and have been divided into 8 parts. Part I provides a general introduction. Chapter 1, written by a worldrenowned nutritionist and a health professional, provides an overview on the epidemiology of obesity. Chapter 2 explains the relationship between obesity and type 2 diabetes. Part II deals with the pathophysiology of obesity. Chapter 3 by Professor Karl-Heinz Wagner and Helmut Brath demonstrates the global view on noncommunicable diseases and where we all are going. This part demonstrates the evidence for refined food addiction; correlates obesity with environmental estrogens and endocrine disruption, cigarette smoking, and inflammatory responses; and elaborates the roles of neurotransmitters, neurobiology, leptin, ghrelin (the hunger hormone), DNA methylation, and sleep. Part III correlates obesity with diverse degenerative diseases, including metabolic syndrome, type 2 diabetes, and diverse inflammatory responses such as wound healing and angiogenesis. Professor George Corcoran, immediate past president of the Society of Toxicology, discusses the role of drug and chemical toxicities in overweight and obesty in Chapter 18. Finally, Professor Merlin Butler emphasizes the genomic imprinting disorders in obesity in Chapter 19.

Part IV starts with Dr. Olivier Boss et al.'s chapter covering new concepts in obesity drug development. This is followed by Dr. Susan Schwartz and Dr. David Savastano's chapter on the history and regulation of prescription and over-the-counter weight loss drugs. The worldrenowned Pennington Biomedical Research Center scientists Dr. Alok Gupta and Dr. Frank Greenway discuss the safety of obesity drugs in Part V. This part is further expanded to discuss the historical perspective of obesity drugs, efficacy of current obesity drugs, and future directions. Part VI consists of 33 chapters on natural, nutritional, and physical approaches of weight management. The roles of exercise and physical activity in weight management and weight loss, the usefulness of pedometers, the nutritional and dietary approaches for weight control, gender effects of adiposity, and antiaging effects of caloric restrictions are thoroughly demonstrated by experts in the field. This part also covers carbohydrate blocks; vegetarian, plant-based, and Atkins diets; the concept of the glycemic index; as well as the roles of chromium (III), (–)-hydroxycitric acid, bitter orange (Citrus aurantium and p-synephrine), conjugated linoleic acid, curcumin, tea, chitosan, Caralluma fimbriata, glucomannan, medium chain triglycerides, marine lipids, calcium and dairy products, the banned weight loss ingredient ephedra, Coleus forskohlii extract, and Lagerstroemia speciosa (coroslic acid) in weight management. There are also two interesting chapters, including a review on weight loss and a chapter providing the reflections of a practicing dietician regarding weight loss supplements. Part VII deals with child obesity—a most challenging issue in the new millennium. Five chapters highlight the intricate aspects of this problem and possible strategies for prevention. Part VIII discusses bariatric surgery and how this may help in weight management and in reversing metabolic disorders.

Finally, we extend our special thanks and gratitude to all the authors for their invaluable contributions and to Randy Brehm and Jill Jurgensen for their continued support.