A gastric bypass is a surgical procedure carried out on the stomachs of patients who are obese and need to lose weight urgently. A gastric bypass is often recommended to patients who have been unable to lose weight by more traditional methods such as strict dieting and intensive exercise programs set by their medical consultants. In the US, those who tend to be considered by their physicians as candidates for gastric bypass surgery are those with a body mass index (BMI) of 40 or more, or, less typically, patients with a BMI ranking between 35 and 40 who also suffer from a serious disease like diabetes that could be significantly relieved by gastric bypass surgery.
The majority of gastric bypass procedures involve restrictive surgery, which is more commonly known as ‘stomach stapling’. This form of surgery involves a reduction in the volume of the patient’s stomach, in order that they begin to feel full after eating much smaller amounts of food. The typical result of this gastric bypass is an accordant decrease in the patient’s calorie intake, causing a reduction in their weight in the medium or long term. The ‘pouch’ of stomach left intact by the gastric bypass surgeon at first holds only one ounce of swallowed food, but in time expands, eventually able to store between two and three ounces. Research suggests that roughly 30% of patients undergoing gastric bypass surgery go on to achieve and sustain an average weight, and that roughly 80% do experience weight loss of some kind.