A diet high in saturated fat and refined sugar can lead to obesity but in also making changes to the brain, it will also result in the desire to overeat these foods.
Terry Davidson, a professor of psychology and director of American University’s Center for Behavioral Neuroscience, explains this link, in saying, “What I think is happening is a vicious cycle of obesity and cognitive decline. 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.”
In the study conducted earlier with rats, and which led to these findings, Davidson gave trained rats a limited amount of low-fat “lab chow” and tested them on two problems. Once the training was complete, one of the groups was given unlimited low-fat lab chow while the other group was given high-calorie food. On this diet, the rats were given the same two tests namely the hippocampus-dependent learning and memory test and another one that did not involve this part of the brain.
What was found was that the latter group, on high-calorie food, was not only obese but also performed worse at the learning and memory test but also failed the blood-barrier tests conducted as well, and which suggested impairment of the brain.
In making the assumption that these findings apply to humans too, this cycle of obesity and cognitive decline can cause people to believe that they can never lose weight and be healthy again.