The rats that had gastric bypass surgery lost weight comparable to humans who received the surgery -- 26 to 30 percent of their weight -- and maintained the loss for a long period of time after surgery. Following surgery, the obese rats also showed a higher tolerance for glucose, indicating improvement in diabetes.

"This supports the applicability of this rat model of Roux-en-Y gastric bypass to humans and also suggests that the observed taste changes following the surgery were not related to 'human factors' such as awareness and compliance to dietary and behavioral interventions," Hajnal said.

The researchers published their findings in the October issue of the "American Journal of Physiology, Gastrointestinal and Liver Physiology." The National Institute of Diabetes and Digestive and Kidney Diseases and the National Institute of General Medical Sciences funded this work.

"These findings confirm obesity-related alterations in taste functions and demonstrate the ability of gastric bypass surgery to alleviate these modifications," Hajnal said. "We do not suggest, however, that the findings reported in this paper are the only neural consequences of gastric bypass surgery related to altered postsurgical food preferences. Nevertheless, understanding the underlying mechanisms by which gastric bypass surgery affects taste may help in identifying therapeutic targets that mimic the beneficial effects of the surgery on appetite control and food choices, without the risks and complications of an invasive surgical procedure."

Source: Penn State