Effect of the gastric balloon versus sham procedure on weight loss in obese subjects.

The mechanism by which intragastric balloons induce weight loss is not known, although they may act simply by reducing the amount of food needed to induce satiety. The knowledge that a balloon is present may influence the patients' eating patterns and reduce caloric intake and weight. In order to test whether the balloon or the secondary psychological effect caused weight loss, a double blind balloon versus sham procedure was devised with both groups receiving identical outpatient dietary advice (800 kcal/day). Twenty four obese women with body mass index greater than 30 kg/m2 from an obesity clinic were studied. Twelve had the balloon and 12 the sham procedure. The balloon was removed after three months and the patients were followed for a further three months. There was significantly greater weight loss in the balloon group, mean weight loss (SD) of 7.33 (6.12) kg compared with the sham group, mean weight loss (SD) of 3.33 (3.9) kg (p less than 0.05). Weight loss was not maintained in all patients after balloon removal. Side effects were more common in the balloon group (abdominal pain, nausea, and vomiting) but resolved by the second week. We conclude that the intragastric balloon is a safe and effective method of inducing weight loss in well motivated obese patients.