Although researchers have unearthed evidence that point towards psychological factors in weight regain after weight loss, the mechanism in which this happens was not known. The latest research on the subject has revealed that when a person loses substantial amount of weight, the hormones in the body that regulate appetite are present in increased levels. This causes a person to eat more and gain back most of the lost weight.

The study was conducted by researcher Dr. Michael W. Schwartz from the University of Washington. He has reported that certain structural changes take place in the brain in areas that causes the triggering of the hormones that are responsible for controlling appetite. The study was conducted on rodents and similar effects are expected in humans as well. The part of the brain that is affected due to obesity is hypothalamus, which is one of the most important parts of the brain. It controls a number of important activities in the body such as body weight. Researchers are of the opinion that the interactions between neuron cells that take place in the hypothalamus prevent permanent weight loss in people who are obese.

Researchers have also said that the neuro-circuits in the brain are responsible for controlling energy balance in the body. Although there were speculations regarding these factors, the present study is the first one that explains the manner in which these things take place in the brain. The impact of high fat diets on the brain was studied in the present research. Evidences obtained from the study apply to rodents such as rats and humans.

During the course of the study, it was found that when rats were engineered to be obese, structural changes took place in their brains very early in life. These changes were analyzed with the help of brain scans. When the brain scans of obese human beings were compared to the scan of rat brains, it was found that the changes were consistent in both. The same area of brain was affected in both the cases.

The lead researcher of the study said that although the study proves evidence of structural damage to the brain in obese beings, the study does not unearth if injury to the brain is the reason why the body tries to gain back weight because higher body weight can help in generating more energy to correct injuries. The study has been collaborated with another test conducted by Dr Jeffrey Flier from the Beth Israel Deaconess Medical Center, Boston.