Some people may treat themselves to greasy fried chicken or decadent desserts every now and then, but know that too much of these foods is not good for their bodies. However, for obese individuals, consuming these unhealthy dining options may actually lead to brain changes that make it hard to stop eating them, according to new research from Terry Davidson, director of American University's Center for Behavioral Neuroscience.

Based on the results of Davidson's rat study, which is published in the journal "Physiology & Behavior," he believes that a diet heavy in saturated fat and refined sugar could alter the hippocampus – the part of the brain that stores memories. Too much unhealthy food in the system may change the hippocampus' ability to suppress the need for more food that is high in calories.

"What I think is happening is a vicious cycle of obesity and cognitive decline," Davidson said. "The idea is, you eat the high fat/high calorie diet and it causes you to overeat because this inhibitory system is progressively getting fouled up. And unfortunately, this inhibitory system is also for remembering things and suppressing other kinds of thought interference."

If individuals feel like changes to the way they think have followed a significant weight gain, they may want to consider taking an IQ test.