Preface

The World Health Organization (WHO) defines overweight and obesity as "abnormal or excessive fat accumulation that presents a risk to health." Although obesity has been recognized as a health problem since the Middle Ages, it was not until the last century that it attracted the attention of medical departments and public health institutions. It is the cause of more than 4 million deaths per year worldwide due to not only metabolic or pathophysiological consequences but also malnutrition and lack of self-care.

Being overweight is a problem that affects half the world's population. The most severe case is the United States, where more than 68% of adults are overweight and 38% are obese. Obesity prevalence has increased globally in many countries regardless of age, sex, race, and smoking status. It has been more noticeable in the higher BMI cases (> 40 kg/m2) than in lower BMI categories (BMI < 35 kg/m2). However, causes in different countries are not fully understood.

Until the first half of the twentieth century, it was thought that persons gained weight simply because they ate too much. As such, dieting was the logical treatment to offer as well as the only treatment available. Nowadays, this thinking is outdated. Obesity is a disease that affects physical, mental, and social wellbeing. Multiple causes affect its development, and dieting is just one aspect of treatment.

Scientific knowledge has increased exponentially in the last 50 years. Biochemistry, pathophysiology, engineering, imaging resources, and computer science have all contributed to a better understanding of how the body works from the architectural to the molecular levels. In addition, psychology is a well-established science whose primary goals are to describe, explain, predict, and change behaviour. It helps individuals make constructive and lasting changes in their lives. Finally, social well-being cannot be fully achieved without the previous two aspects of health (physical and mental spheres).

There is a large amount of information on bariatric surgery, mainly on surgical techniques. Nowadays, the bariatric patient has to be considered as a whole, according to the WHO's definition of health. Surgery alone has a low rate of success. Bariatric treatment requires teamwork as well as dietary, social, and psychological evaluations to establish an individualized management plan that includes discharge and follow-up strategies. Besides surgical options, there are other options to offer the obese patient, including physical exercise, psychological and social support, nutrition, and pharmacological options. More recently, enhanced recovery after surgery (ERAS) protocols have highlighted the role of the anaesthesia team and perioperative care.

This book brings the reader closer to this multidisciplinary approach concept, exhibiting bariatric surgery from the non-surgical approach to post-surgery individual care, taking into account the wide range of professionals that deal with obese patients during and after treatment.
