Data suggest that gastric bypass has more profound effects on the gut milieu than restrictive operations such as laparoscopic adjustable gastric banding. The immediate change in insulin sensitivity also does not occur with medical weight loss alone, which suggests that gastric bypass surgery alters specific aspects of the gastrointestinal hormonal environment that are presently incompletely understood. Improvements in other cardiac risk factors, such as normalization of blood pressure and lipids, also occur in conjunction with laparoscopic adjustable gastric band and/or medical weight loss and tend to be apparent after a 5% to 10% change of initial body weight.
