The research, to be presented at the Annual Meeting of the Society for the Study of Ingestive Behavior (SSIB), explains that eating chocolate stimulates part of the rat’s brain called the orexin system, activating orexin neurons – which are associated with eating particularly tasty foods as well as taking addictive drugs.
The researchers trained rats to expect a piece of chocolate in certain environmental conditions. They found that when mice were placed in the same environment with no chocolate, the orexin system of the brain was still stimulated, perhaps explaining why people have a tendency to overeat in situations where they have previously eaten well, even when they are not hungry.
Lead researcher Derrick Choi said: “It entirely possible that future treatments for obesity will involve a combination of lifestyle changes as well as pharmacological therapies aimed at orexin and other brain systems, to regulate food reward-related behaviors.”
“Our research program is focused on identifying brain systems that are activated by palatable food intake. The hypothalamic orexin system is known to promote wakefulness and arousal; however, it is now clear that this system also participates in the regulation of reward-related behaviors, including overconsumption of palatable foods,” said Choi.