Bariatrics

Bariatrics is the branch of medicine that deals with the causes, prevention, and treatment of obesity. The term bariatrics was created around 1965, from the Greek root baro ("weight," as in barometer) and suffix -iatrics ("a branch of medicine," as in pediatrics). Besides the pharmacotherapy of obesity, it is concerned with obesity surgery.

Overweight and obesity are rising medical problems of pandemic proportions. There are many detrimental health effects of obesity: heart disease, diabetes, many types of cancer, asthma, obstructive sleep apnea, chronic musculoskeletal problems, etc. There is also a clear effect of obesity on mortality, though this is not so clear for those who are overweight.

Diagnosis
Although not a Direct measure of body fat, the Body Mass Index is widely adopted and promoted as a marker for excess body weight. However, it is not flawless: a very muscular person may be assessed as obese, and an elderly person with low body weight but high body fat (this can happen due to low muscle mass and bone density) may be assessed as healthy. Other markers for the evaluation of obesity include waist circumference (associated with central obesity), and a patient's risk factors for diseases and conditions associated with obesity. Besides these indirect methods, body fat can also be measured directly.

General aspects of treatment
Although diet, exercise, behavior therapy and anti-obesity drugs are first-line treatment, medical therapy for severe obesity has limited short-term success and almost nonexistent long-term success. Therefore, obesity surgery (or bariatric surgery) has been a popular treatment in the war against obesity. Weight loss surgery generally results in greater weight loss than conventional treatment, and leads to improvements in quality of life and obesity related diseases such as hypertension and diabetes.

Before someone can become eligible for bariatric surgery, certain criteria must be met. The basic criteria are an understanding of the operation and the lifestyle changes the patient will need to make, and either:
 * a body mass index (BMI) of 40 or more, which is about 45 kg (100 pounds) overweight for men and 35 kg (80 pounds) for women; or
 * a BMI between 35 and 39.9 and a serious obesity-related health problem such as type 2 diabetes, heart disease, or severe sleep apnea (when breathing stops for short periods during sleep)

Past studies found that 10 percent to 20 percent of bariatric surgery patients had complications while they were in the hospital. In 2006, federal researchers found that 39.6 percent of patients had complications within 180 days of surgery. The most common complications are About 7% of patients were readmitted to the hospital within 6 months to treat complications specific to the bariatric procedure. There were 212 in-hospital deaths out of an estimated 104,702 adults who underwent obesity surgery in 2003, or a rate of 0.2 per cent.
 * a composite of gastrointestinal symptoms including vomiting, diarrhea, dysphagia, and reflux (20%)
 * anastomotic leaking (at the surgical connections between the stomach and the intestine) (12%)
 * abdominal hernia (7%)
 * and "infections" (6%).

The prevalence of extreme obesity (body mass index > or = 40 kg/m²) in the United States in 2003-2004 was 2.8% in men and 6.9% in women. This suggests millions of people are in the weight range for potential therapy with bariatric surgery. Laparoscopic surgery has become an important addition to this field of surgery, and demand soars, amidst scientific and ethical questions. The number of Americans having weight-loss surgery more than quadrupled between 1998 and 2002—from 13,386 to 71,733—according to a study by the Agency for Healthcare Research and Quality.

Surgical procedures
There are a number of surgical options available to treat obesity, each with their advantages and pitfalls. In general, weight reduction can be accomplished, but one must consider operative risk (including mortality) and side effects. Usually, these procedures can be carried out safely. Procedures can be grouped in three main categories:
 * predominantly malabsorptive procedures: although also reducing stomach size, these operations are based mainly on malabsorption.
 * Biliopancreatic Diversion (Scopinaro procedure - rare)
 * Jejuno-ileal bypass (no longer performed)
 * predominantly restrictive procedures: this kind of surgery primarily reduces stomach size
 * Vertical Banded Gastroplasty (Mason procedure, stomach stapling)
 * Adjustable gastric band (or "Lap Band")
 * Sleeve gastrectomy
 * Mixed procedures: applying both techniques simultaneously
 * gastric bypass surgery, like Roux-en-Y gastric bypass
 * Sleeve gastrectomy with Duodenal Switch
 * Implantable Gastric Stimulation

Anti-obesity drugs
If diet and exercise are ineffective alone, anti-obesity drugs are a choice for some patients. Prescription weight loss drugs are recommended only for short-term use, and thus are of limited usefulness for extremely obese patients, who may need to reduce weight over months or years.