Obesity as a Disease: Etiology, Treatment, and Management Considerations for the Obese Patient

Overweight and obesity have reached epidemic proportions in the United States, increasing among all age, race, and ethnic groups and in both men and women. The most recent survey from the National Health Examination Survey (NHANES) for 1999 to 2000 reported the age-adjusted prevalence of overweight [defined as body mass index (BMI) ≥25 kg/m2] as 64.5% and obesity (defined as BMI ≥30 kg/m2) as 30.5% for U.S. adults (1). These recent figures represent increases in the prevalence of overweight and obesity by 8.6% and 7.6%, respectively (p < 0.001) since NHANES III (1998 to 1994). (1). Today, the prevalence of obesity and overweight continues to increase dramatically, in part, as an unintended consequence of the economic, social, and technological advances that have contributed to unhealthy dietary habits and sedentary behavior during the past several decades. As the second leading cause of preventable death in the U.S. today, accounting for ∼300,000 deaths per year (2), overweight and obesity pose a major public health challenge. The prevalence of obesity and overweight is influenced by a complex interaction of genetic, environmental, and behavioral factors. Obesity occurs when caloric intake exceeds energy expenditure, but a growing body of evidence supports the view that obesity is caused by inherited tendencies to subtle disorders of the weight-regulating mechanism magnified by a poor diet and lack of activity practiced by most of the population. Nonetheless, obesity continues to be viewed by many as a behavioral disorder. It is crucial that physicians and their staff are supportive, nonjudgmental, sensitive, and compassionate when treating obese patients. An increased BMI, particularly when it is associated with abdominal or upper-body obesity, has been linked with a number of diseases and metabolic abnormalities. Obese individuals also suffer from social stigmatization, discrimination, and low self-esteem. Thus, weight loss is an important goal for the obese patient because it can improve many of the medical illnesses associated with obesity and prevent the development of new obesity-related diseases. Managing obesity requires lifelong treatment, as is required for the management of chronic diseases associated with obesity, such as diabetes and hypertension. Despite the magnitude of the problem of obesity, most health-care providers feel uncomfortable dealing with it. This has led to the publication of a set of guidelines on the treatment of obesity by the National Institutes of Health urging health-care providers to address obesity in the office setting (3). Health-care providers are uniquely qualified to manage obesity and encourage healthy weight maintenance within the primary-care setting. Through routine assessments of BMI and waist circumference at each office visit, health-care providers have an opportunity to counsel patients on the prevention of obesity, to intervene early with at-risk patients, and to encourage overweight patients to begin or continue weight management programs. A successful weight management plan can be better implemented when there is a physician–patient partnership and when proper office-based obesity care is practiced. To accommodate the obese patient, the office environment should be comfortable, accessible, and equipped appropriately with available educational materials regarding health concerns and treatment options for obesity. A team approach toward weight management involving the physician's staff can increase patient compliance and long-term success. Once a patient at increased medical risk from overweight or obesity has been identified, the medical history and physical examination should include assessment for potential causes and complications of obesity. After the patient's weight-related risk assessment, readiness and motivation to lose weight should be determined. Patients who are unready or unwilling to lose weight rarely succeed in a weight-loss program (4). Patients who are not ready to lose weight and who are not at high risk should be encouraged to maintain their current weight through a healthy lifestyle, and any complications of obesity should be managed appropriately. For high-risk patients, the clinician should make an effort to motivate the patient by discussing the benefits of weight loss, including the health improvements seen with a small but achievable reduction in body weight. For patients who are ready to lose weight, the initial treatment of obesity should focus on implementation of a diet and exercise program tailored to his or her lifestyle and physical needs. Reasonable goals for diet and physical activity should be set. For most patients, this translates into a 5% to 10% reduction in body weight—a degree of weight loss that can significantly decrease the severity of obesity-associated risk factors. When combined with a low-calorie diet, a daily exercise program that is customized to the patient's physical condition and ability is essential for achieving and maintaining weight loss. To overcome obstacles to compliance with dietary therapy or physical activity, behavior therapy should be implemented. In some cases, a patient is able to provide his or her own support for making modifications in lifestyle, whereas others might derive greater benefits from professional support. For patients who cannot achieve sufficient weight loss through lifestyle and behavioral modification, drug therapy can be implemented in certain circumstances for the treatment of obesity. Weight-loss drugs approved by the Food and Drug Administration may be used as adjunctive therapy in patients with a BMI of ≥30 kg/m2 or in patients with a BMI of ≥27 kg/m2 who also have other risk factors or diseases. Only two drugs, sibutramine and orlistat, have been approved by the Food and Drug Administration for long-term use. In patients with clinically severe obesity—a BMI of ≥40 kg/m2 or a BMI of ≥35 kg/m2 with high-risk comorbid conditions—and in whom other methods of treatment have failed, weight-loss surgery is an option. In most patients, weight-loss surgery has been shown to provide medically significant sustained weight loss for more than 5 years. The two most common procedures are gastroplasty and Roux-en-Y gastric bypass. Regardless of the type of surgery performed, lifelong medical surveillance after surgery is necessary. As the prevalence of overweight and obesity in the U.S. continues to rise, and our treatments improve based on a better understanding of the disorder, the treatment of obesity may soon replace the treatment of its complications. At present, identifying people at risk from obesity and its related comorbidities is an important goal for the health-care provider. Proper identification, classification, assessment, and treatment of obesity are necessary components to successfully manage obesity. Ultimately, active involvement from the physician will assist the patient's efforts to initiate and maintain weight-loss and healthy-lifestyle practices.