Overeating and addiction linked

The same brain circuits are involved when obese people fill their stomachs as when drug addicts think about drugs, a finding that suggests overeating and addiction may be linked, U.S. researchers have reported.

The finding may help in creating better treatments for obesity.

“We wanted to know why, when people are already full, why people are still eating a lot,” said Dr. Gene-Jack Wang of Brookhaven National Laboratory in Upton, N.Y.

He and his colleagues tested seven obese volunteers who had been fitted with a gastric stimulator -- a device that tricks the body into thinking the stomach is full, a state known as satiety.

They used a positron emission tomography, or PET, scan to see which parts of the brain activated when the stimulator was activated.

“We thought the activated area [of the brain] must be in the satiety center, which we learned in medical school is supposed to be in the hypothalamus,” Wang said in a telephone interview.

But they did not see activity there.

“We saw a lot of activity in all areas of the brain, especially in the hippocampus. That region is related to learning, memory and is also related to a lot of things such as sensory and motor impulse and emotional behavior,” Wang said.

The study was published Thursday in the online version of Proceedings of the National Academy of Sciences.