When you're a little hungry, how do you feel? Smart, sharp and ready to take on the world — or utterly obsessed with food?

Researchers say that occasional fasting may boost your brain's ability and that's likely due to what's often called "the hunger hormone."

The Significance of Ghrelin

Ghrelin is a hormone primarily released in the stomach that signals to the brain that you're hungry. Researchers generally believe that ghrelin levels increase during times of fasting when you're hungry and usually drop several hours after eating, according to WebMD.

But Jeffrey Davies, an associate professor of molecular neurobiology at Swansea University in the United Kingdom, says ghrelin does more than signal hunger. Davies has published several studies on the power of ghrelin and says the hormone can stimulate the growth of brain cells and improve memory in mice. His team's work was recently presented at the British Neuroscience Association.

One function of the hormone is to respond to changes in the environment, he says.

"This 'homeostatic' function sees it being released during periods of calorie restriction to activate mechanisms to trigger feeding and restore a healthy metabolic state. As part of this homeostatic response, ghrelin seems to prime other physiological aspects to improve the chances of survival, i.e improving memory function."

In studies where mice are given 70 percent of what they'd normally eat for 14 days, they grow more neurons in the part of the brain known as the learning and memory center. This process, called neurogenesis, goes hand-in-hand with improved performance on long-term memory tests.

Implications of the Studies

Davies says the practical ramifications of fasting may be translated from mice to humans.

"The message that mild calorie restriction is beneficial to health is supported by clear evidence," he says. "For the general population that is something that they may be able to introduce into their lives, similar to increasing the amount of exercise they take part in."

So maybe skip lunch before your next big meeting so your brain cells can divide and multiply and give you a cognitive boost?

"I don’t think it's a great idea," Davies says. "Just in case you pass out from hypoglycemia!"