This is one the most commonly performed weight loss surgeries in the United States of America and worldwide. Every other weight loss surgery is compared to the roux-en-y gastric bypass to determine success.
The Roux-en-Y gastric bypass surgery has been performed for many years for weight management. It has a long and proven track record of effectiveness. As previously mentioned, generally this is the operation that other operations are compared with and thus is thought of as the gold standard. It has been extensively performed for weight loss since the late 1960's.
The gastric bypass surgery leads to weight loss by multiple mechanisms. First, it reduces the size of the stomach which decreases the amount of food that can be consumed before feeling full and satiety. Second, it bypasses a portion of the small intestine which reduces the amount of the food that can be absorbed by the body further leading to weight loss.
On average, patients lose 65-80% of their excess weight with this surgery. There are many health conditions which are resolved or markedly improved with gastric bypass surgery. In several studies, greater than 90% of patients had resolution of their hypertension (high blood pressure), diabetes, hyperlipidemia (high cholesterol) and sleep apnea.