The purpose of the operation is to drastically decrease the amount of food eaten without causing hunger. Appetite is significantly controlled by the restrictive effect of the new stomach and the hormonal change, leading to an early feeling of fullness.

Candidates for laparoscopic sleeve gastrectomy must have an excessive weight of greater than 45 kg (100 lb) or a body mass index (BMI) of greater than 40 kg per square meter. Those with a BMI of 35-40 kg per square meter may be considered candidates for surgery if they suffer from obesity-related comorbid conditions, such as diabetes, heart disease, hypertension, sleep apnea, pain in weight-bearing joints that interfere with daily life, etc.

The operation is performed through laparoscopy, with four small incisions of one to two centimeters each made in the abdomen. The remaining 75% to 80% of the stomach is then removed. This minimally-invasive procedure requires just a short stay at the hospital.

Major surgical complications requiring a second operation to fix occur in about 1% of patients and include bleeding, infection, leakage, adjacent organ injury, and intestinal obstruction. Risks from developing blood clots in the deep veins of the legs and the lungs are minimized by prophylactic blood thinner, leg pumps and early ambulation.

After surgery, eating habits need to be adjusted to the smaller stomach capacity. Failure to control eating behaviors and repeated overeating may cause excessive vomiting. Otherwise, a mild degree of nausea and vomiting can occur during the first few months following surgery.

When the degree of excess weight reaches the level of morbid obesity (BMI of greater than 40 kg/m²), other endoscopic or nonsurgical interventions might not be able to achieve effective weight loss in the vast majority of patients, greater than 95%. Surgical weight loss is currently the only effective and long-lasting method of weight control in patients with morbid obesity, with an 85% success rate for laparoscopic gastric bypass operations. In the setting of morbid obesity, other less effective operations, including laparoscopic gastric banding and sleeve gastrectomy, are not recommended.