People who undergo gastric bypass surgery -- a procedure used to treat those who are morbidly obese -- often experience a loss of appetite after the procedure. But doctors haven't quite understood the reasons why.
Now researchers at Emory University in Atlanta have found that, within minutes after the surgery, people experience a drop in levels of a hormone that helps induce the hunger sensation.
The stomach is the main factory for the hormone ghrelin. During gastric bypass, surgeons divide the stomach and make a small pouch that attaches to the small intestine, cutting off primary production of the hormone.
In 34 gastric bypass patients, levels of ghrelin in the blood began to fall 30 minutes after the stomach was divided and had decreased by almost a third 10 to 15 minutes after the surgery was completed, says Edward Lin, assistant professor of surgery at Emory.