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.

# Healthy lifestyle
Healthy lifestyle changes such as dieting and improvements in health behavior can be fostered by methods of patient engagement.

# 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.

# Bariatric surgery
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
- 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%).
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.
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 2002from 13,386 to 71,733according 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)
- 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
- 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
- gastric bypass surgery, like Roux-en-Y gastric bypass
- Sleeve gastrectomy with Duodenal Switch
- Implantable Gastric Stimulation

# Footnotes
-  The American Heritage Dictionary of the English Language, 4th edition, Houghton (2000): "Bariatrics" Retrived 14 Feb. 2006
-  Dictionary.com, based on Random House Unabridged Dictionary, Random House (2006):  Retrieved 15 Apr. 2006
-  Reynolds K, He J. Epidemiology of the metabolic syndrome.Am J Med Sci 2005;330:273-9. PMID 16355011
-  Hedley AA, Ogden CL, Johnson CL, et al. 2004. Prevalence of overweight and obesity among US children, adolescents, and adults, 19992002. JAMA ; 291: 284750. PMID 15199035
-  WHO factsheet on obesity
-  Flegal KM, Graubard BI, Williamson DF, Gail MH. Excess deaths associated with underweight, overweight, and obesity. JAMA  2005; 293: 1861-7.
-  Obesity: preventing and managing the global epidemic. Geneva, World Health Organization (WHO Technical Report Series, No. 894).
-  Jump up to: 8.0 8.1 Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults, The Evidence Report. NIH Publication NO. 98-4083, september 1998. NATIONAL INSTITUTES OF HEALTH National Heart, Lung, and Blood Institute in cooperation with The National Institute of Diabetes and Digestive and Kidney Diseases.
-  Jump up to: 9.0 9.1 Gastrointestinal surgery for severe obesity: National Institutes of Health Consensus Development Conference Statement. Am J Clin Nutr 1992;55(S2):615S-619S. PMID 1733140
-  Colquitt J, Clegg A, Sidhu M, Royle P. Surgery for morbid obesity. Cochrane Database Syst Rev 2003; 2: CD003641. PMID 12804481
-  Gastrointestinal surgery for severe obesity. U.S. Department of Health and Human Services, National Institutes of Health. NIH Publication No. 04-4006, December 2004.
Agency for Healthcare Research and Quality: Obesity Surgery Complication Rates Higher Over Time. Press Release, July 24, 2006. Retrieved July 24, 2006
-  Encinosa WE, Bernard DM, Chen CC, Steiner CA (2006). "Healthcare utilization and outcomes after bariatric surgery" (Abstract). Medical Care. 44(8): 70612. Retrieved 2006-08-08.CS1 maint: Multiple names: authors list (link) .mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
-  Ogden CL, Carroll MD, Curtin LR, McDowell MA, Tabak CJ, Flegal KM. Prevalence of overweight and obesity in the United States, 1999-2004. JAMA 2006; 295:1549-55. PMID 16595758
-  Mitka M. Surgery for obesity: demand soars amid scientific, ethical questions. JAMA 2003; 289: 1761-2.
-  Agency for Healthcare Research and Quality: AHRQ Study Finds Weight-loss Surgeries Quadrupled in Five Years. Press Release, July 12, 2005 Retrieved July 24, 2006
-  Nguyen NT et al. Result of a national audit of bariatric surgery performed at academic centers: a 2004 University HealthSystem Consortium Benchmarking Project. Arch Surg 2006; 141: 445-9. PMID 16702515
-  Abell TL, Minocha A. Gastrointestinal complications of bariatric surgery: diagnosis and therapy. Am J Med Sci 2006;331: 214-8.