The food cravings experienced by some obese patients are due to the same brain circuits that cause cravings in drug addicts, a study has revealed.
Researchers at the US Department of Energy's Brookhaven National Laboratory have discovered that the same circuits play an important role in soothing negative emotions.
Brain scans were taken of seven obese patients, all of whom had gastric stimulators implanted in their stomachs.
The devices stimulated the vagus nerve, causing the stomach to produce peptides which signal to the brain that the stomach is full.
Messages relaying fullness were sent to the hippocampus and to brain circuits in the orbitofrontal cortex and striatum, which have been linked to drug cravings in patients with addictions.
The authors believe that memories of fullness in obese patients might be stimulated by the hippocampus and conclude that the connections between stomach, hippocampus and the emotions should now be studied with a view to potentially treating and preventing obesity.
Lead author Dr Gene-Jack Wang said that the study "opens new territory in understanding how the body and brain connect to each other, and how this connection is tied to obesity".
"We were able to simulate the process that takes place when the stomach is full, and for the first time we could see the pathway from the stomach to the brain that turns 'off' the brain's desire to continue eating," he revealed.