Understanding Obesity

Introduction There's No "One- Size-Fits-All" Method for Losing WeightThis book is intended as a guide for anyone who is overweight and looking for sensible approaches for dealing with the problem. In these pages I describe what we currently know about the causes and management of obesity. We are on the verge of having a useful understanding of the complex reasons why people become obese, and I discuss these in some depth. It is only fair to warn you, however, that completely successful methods of weight loss are still far off, and successful long-term treatments are difficult to devise.Let us start with two basic questions. First, what is obesity? And second, why should anyone worry about it? The World Health Organization's criteria for Body Mass Index (BMI) have recently been adopted as the universal standard for defining levels of overweight and obesity. (The Body Mass Index is your weight in kilograms divided by the square of your height expressed in centimeters.) A Body Mass Index of less than 18.5 signifies malnutrition or significant underweight, a BMI from 18.5 to 24 is normal, from 25 to 29 is overweight, and above 30 indicates obesity. Though using BMI alone as a measure of weight problems has its limitations (as will be discussed later), according to the recent Canadian Heart Health Survey, approximately 44 percent of men and 25 percent of women have a BMI of 25 to 29 (overweight). Thirteen percent of men and 14 percent of women have a BMI over 30 (obese). Therefore, if we take a BMI of 24.9 as the cutoff above which an individual is too heavy, 57 percent of men are overweight or obese and 39 percent of women are in the same category. Thus, fully 48 percent of our adult population are excessively heavy. In the United States, using slightly different cut-offs for BMI, 31 percent of adults have a BMI of 25 to 30, and 21 percent have a BMI above 30 and so are obese.There is also a very disturbing trend in the development of weight problems in our children. In 1981, 15 percent of children were overweight or obese, while in 1998, 24 percent were overweight or obese. (The concept of an "ideal" weight raises further questions, but for now let's accept that there is an approximate "healthy" weight for most people.)The reason we need to be concerned is that excess weight is the cause of more illness than virtually any other medical condition. Even in the poorest countries, obesity is becoming epidemic, causing significant ill health from diabetes and heart disease where these were relatively rare thirty years ago. In the western industrialized countries, many more people will have to see a doctor because of complications arising from overweight than will develop cancer! For example, 80 percent of adult-onset diabetes occurs in people who are overweight or obese. Diabetes, heart and vascular disease, high-blood pressure (hypertension), gallbladder disease, arthritis, sleep apnea (a condition where people fail to breathe adequately during sleep), and gastrointestinal ailments are just some of the health problems that can afflict the overweight person.Not surprisingly, the medical and socioeconomic costs of obesity are high. Of all the health-care dollars spent in the United States in 1990, 6.8 percent (about $34 billion) were spent on the physical and psychological treatments directly associated with obesity. In Canada, 2.4 percent of the health care budget was spent for these problems. It is important to note that these costs are for the treatment of obesity-related problems (such as heart disease) only and do not include the additional costs that occur where, for example, wages are lost due to obesity-linked illness such as arthritis, high blood pressure, and early death. From a public-health perspective, allowing this illness to remain so poorly researched and treated has beenLevy, Lance is the author of 'Understanding Obesity', published 2000 under ISBN 9781552094792 and ISBN 1552094790.