Bariatrics is the field of medicine that is concerned with the causes, prevention, and treatment of obesity. As of the mid-2000s, according to the American Heart Association (AHA), the proportion of individuals who are overweight or obese in the United States is estimated to surpass 45% of the adult population (20 years or older). Such a staggering statistic has associated with it profound ramifications. Excess weight is a major contributor to serious health conditions that affect millions of people and can result in early death. Aside from tangible diseases, obesity is the root of much psychological distress, which adds to the negative impact of being overweight. As the social pressure to be thin climbs in importance, the number of obese individuals also continues to rise, creating a potentially devastating emotional and physical dilemma for many. Additionally, the overall cost of health care is increased by obesity in this country and in other post-industrialized nations. As health care resources become more limited, then, potentially preventable conditions such as obesity are being pushed into the spotlight of managed care concerns. As a result, many different facets of bariatric medicine have emerged that try to reduce obesity effectively and safely.
Just as cardiac surgeons treat heart conditions, and podiatrists manage diseases of the feet, bariatric physicians are concerned with weight loss. Bariatrics utilizes varied techniques to reduce body fat. Among these are surgical procedures like gastric (or stomach) bypass, cosmetic procedures such as liposuction, or pharmaceutical therapies that use drugs to reduce weight. Bariatrics also includes special dieting techniques and exercise regimens, often tailored to meet individual needs. While even a small reduction in weight is known to have beneficial impacts on health, some bariatric methods are controversial because they have significant health risks of their own.
Obesity can be defined as a body weight that is in excess of 20 to 30% of one’s ideal weight. In order to fit this definition, though, the excess weight must be from fatty tissue, or adipose tissue. Muscle mass is not counted in obesity weight measurements. Obesity is detrimental because it can cause or contribute to the development of many other very serious health problems. Obesity, and simply being overweight, has been linked to coronary artery disease and congestive heart failure, non-insulin dependent diabetes mellitus (also called adult-onset diabetes), gout and gallstones, some forms of cancer, and arthritis. Some medical experts contend that obesity has reached epidemic proportions in the United States. The increase in obesity, and associated illness, might be the result of the stresses of modern lifestyles where time is limited; high calorie (often times fast-food restaurant) types of food is abundant, and physical activity is reduced.
Obesity is a persistent, continuing disease caused by many factors. However, a useful and precise definition of obesity has been elusive. This is generally because many factors can influence the weight of a person. Diet, gender, exercise frequency, genetics factors, and environment all contribute to weight. Regardless of the lack of a distinct definition, obesity, as of 2005 (according to the AHA), is charged with over 100,000 preventable deaths in the United States each year. Second only to the effects of cigarette smoking and other tobacco use, obesity costs are estimated to exceed $100 billion per year, and continues to increase. As a whole, the portion of American society considered to be obese rose from 25% to over 38% from 1991 to 2002 and has climbed to over 45% as of 2005. Therefore, the demand for bariatric services has also increased proportionally.
Just as there are many factors contributing to obesity, bariatrics utilizes many techniques to control weight and induce weight loss. Although bariatric medicine is concerned with all methods of weight loss including nutrition and exercise, the term is used almost synonymously with surgical procedures. Such techniques include cosmetic procedures such as liposuction and somewhat radical operations like gastric resections. In addition, drug therapy is often employed in the fight for weight loss. Pharmaceuticals are used alone or in combination to reduce appetite or inhibit the metabolism of ingested fats. The ease of taking pills to reduce body fat make pharmaceuticals attractive to many. However, side effects and the potential for abuse of medications can be significant.
The surgeries most often used to cause weight loss are restriction operations. Restriction operations limit or restrict food intake by creating a small pouch at the top of the stomach where the food enters from the esophagus. The reduced outlet delays the passage into the stomach and results in a sensation of fullness after eating very little food. The effect is like creating a tiny stomach on top of the existing stomach. The patient, then, perceives only the filling of the tiny stomach. After an operation, the person usually can eat only one-half to one whole cup of food without discomfort or nausea. Most people cannot eat normal quantities of food. As a result, patients lose weight.
Restriction operations include gastric banding and vertical banded gastroplasty. Both operations serve only to restrict food intake, maintaining normal digestive processes. In gastric banding, a band made of surgical material restricts food movement near the upper portion of the stomach leaving a small passage for food to enter the rest of the stomach. Vertical banded gastroplasty is more prevalent and uses surgical staples to limit access of food to the stomach. Restrictive operations induce weight loss in nearly all patients. Unfortunately, some patients regain the weight that was lost. Because some patients are unable to modify their eating habits, restriction operations have limited success. Only about 30% of people reach normal weights after vertical banded gastroplasty. However, nearly 80% achieve some degree of weight loss.
Gastric bypass operations combine the creation of small stomach pouches to restrict food intake and the construction of paths for food to bypass the small intestine to cause malabsorption, or a lack of adequate nutrient and vitamin absorption into the body. Some gastric bypass surgeries are extensive, involving major portions of the stomach. Because they completely bypass major regions of food absorption, gastric bypass surgeries are more effective in causing weight loss than restrictive operations. Bypass operations generally result in a loss of two-thirds of one’s body weight within two years. However, the weight loss comes with severe drawbacks. Because essential vitamins and minerals are obtained from food in the stomach and small intestine, gastric bypass prevents their absorption. Therefore, major vitamin deficiencies can be induced. For instance, anemia may result from insufficient absorption of vitamin B12 and iron. Accordingly, patients are required to take nutritional supplements. Also, the more extensive the bypass operation, the greater is the risk for complications, sometimes requiring the life-long use of special foods and medications.
Lipectomy is the surgical removal of fatty tissue from the body. Liposuction, a specific kind of lipectomy, is the surgical removal of fat from beneath the surface of the skin using suction or vacuum techniques. Most often, it is used to reduce adipose tissue from limited areas of the body, and therefore is considered to be a cosmetic procedure, or one that primarily improves appearance. One method of liposuction in weight control is to inject large volumes of saltwater, or saline, containing a local anesthetic into the patient. The solution also contains adrenaline. The anesthetic numbs the procedure area, and the adrenaline constricts blood vessels to minimize bleeding, bruising, and swelling during the procedure. Adipose tissue is then removed by suctioning. Generally, only people slightly overweight benefit from liposuction. Because liposuction is surgical, there are some risks involved even though the procedure is considered very safe. While uncommon occurrences, infection, excessive bleeding, and occasional nerve damage can occur.
Drug therapy in bariatrics
Most of the medications that are used in bariatric treatment are appetite suppressants. These pharmaceuticals promote weight loss by decreasing appetite or increasing a sensation of fullness. Often, these medications work by increasing the action of neurotransmitters, substances that nerve cells release to chemically communicate with one another. Two brain neurotransmitters that can affect appetite are serotonin and the catecholamines. Because of their potency and wide
Adipose— Fatty tissue.
Bariatrics— The field of medicine concerned with the causes, prevention, and treatment of obesity.
Liposuction— The surgical removal of adipose tissue using suction techniques.
Obesity— A metabolic condition of excess weight defined by some as a body weight over 30% of an ideal value.
Restrictive operations— Bariatric procedures designed to promote weight loss by restriction the volume of food that can physically pass through the stomach. Stomach stapling is an example of a restrictive operation.
physiological effects, most appetite suppressants are approved for short-term use only. An exception is Sibutramine, an appetite suppressant that can be used to treat obese individuals for extended periods of time. In general, appetite suppressant medications used in bariatric treatment have only limited effectiveness. Average weight loss using such medications ranges from 5 to 22 lb (2.3 to 10.0 kg). Some obese individuals, however, may lose up to 10% of their body mass. Amphetamine drugs can result in greater weight reduction, but their use is highly regulated because of their potential for abuse and dependence. In some cases, bariatric physicians will utilize a combination of drugs to maximize weight loss. An example is the concurrent use of fenfluramine and phentermine, called Fen/Phen. Fen/Phen was implicated in a number of serious adverse reactions and is, therefore, no longer used. (In March 2003, for example, the death of major league baseball pitcher [Baltimore Orioles] Steve Bechler was linked to use of the diet drug ephedra.)
Often, bariatric treatment uses multiple approaches to manage weight loss. For instance, liposuction may address cosmetic concerns and reduce some bulk weight, while diet and behavioral regimens are taught to the same individual to reduce caloric intake. Furthermore, drug therapy may be used to reduce the absorption of fats from the diet and psychotherapy to address emotional issues may also be administered at the same time. In this multiple approach, many techniques are used simultaneously to induce and maintain weight loss for individuals who find weight loss to be very difficult. Often perceived as the result of a lack of willpower, weakness, or a lifestyle choice of overeating, obesity is in reality a chronic condition that is the result of many interacting factors that include genetics, environment, and behavior. As weight problems persist and increase in the United States, the need for new and effective bariatric treatments will continue to rise.
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