Obesity is caused by a combination of genetics, environmental issues, and behavioral factors. [1, 2] Consumption of high-calorie foods, consumption of too much food, and a sedentary lifestyle all work together to create this condition. Obesity is associated with the development of diabetes mellitus, hypertension, dyslipidemia, arthritis, sleep apnea, cholelithiasis, cardiovascular disease, and cancer.
More than 100 million Americans (65% of the adult population) are overweight.  Obesity is the second-leading cause of preventable death in the United States, after smoking. Obesity-related diseases account for 400,000 premature deaths each year. 
Obesity can be treated medically and surgically. Medical treatment for obesity is challenging, because the amount of weight lost is relatively insignificant and patients tend to regain most of the lost weight. A 2010 prospective, randomized controlled trial in 50 adolescents demonstrated that a greater percentage of patients achieved a loss of 50% of excess weight with laparoscopic gastric banding than with lifestyle intervention. 
Operations that are designed to cause significant and long-lasting weight loss in patients who are severely obese are forms of bariatric surgery, a term derived from the Greek words baros ("weight") and iatrikos ("pertaining to a physician"). Laparoscopic gastric banding, described here, is one such surgical procedure; this procedure falls under the subcategory of restrictive bariatric surgery. Another form of bariatric surgery is gastric bypass (see Laparoscopic Gastric Bypass).
Body mass index (BMI) describes relative weight for height and correlates significantly with an individual’s total body fat.  BMI is based on height and weight and applies to adults of both sexes. It is calculated in either of two ways, as follows [1, 4] :
BMI = weight (kg)/height (m 2)
BMI = weight (lb)/height (sq in.)
In 1991, the National Institutes of Health (NIH) provided a consensus statement for selecting bariatric surgery candidates.  Patients were considered candidates for surgery if they met one of the following criteria:
BMI greater than 40
BMI of 30-40 plus one of the following obesity-associated comorbidities: severe diabetes mellitus, pickwickian syndrome, obesity-related cardiomyopathy, severe sleep apnea, or osteoarthritis interfering with lifestyle
To be candidates for bariatric surgery, patients should have attempted, without success, to lose an appropriate amount of weight through lifestyle changes or through supervised dietary changes.  Patients must also comply with postoperative diet and exercise.
In 2008, the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) issued guidelines for the clinical application of laparoscopic bariatric surgery.  The SAGES guidelines noted that well-selected patients who have a BMI higher than 60 or are older than 60 years may benefit from laparoscopic bariatric surgery by experienced surgeons and that adolescents may also benefit from such surgery.
In February 2011, the US Food and Drug Administration (FDA) expanded the use of the Lap-Band System (Apollo Endosurgery, Austin, TX) for patients with a BMI of 30-34 and having any obesity-associated comorbidities.
Contraindications for laparoscopic gastric banding include the following:
History of substance abuse
An active major psychiatric disorder
End-stage organ disease (eg, cardiac, hepatic, or pulmonary)
Stomach or intestinal disorder or infection
Inability or unwillingness to follow dietary recommendations
Laparoscopic gastric banding appears not to have long-term outcomes as good as those of gastric bypass. [6, 7] In the long term, there is a substantial risk that band removal may prove necessary. A study by Tammaro et al found the risk of removal to be higher in women, younger patients, and individuals with a BMI higher than 50.