Prolonged obesity and the habit of overeating over a period of time causes structural changes in the brain. This leads to the damage of signaling pathways in the hypothalamus in the brain, the part that regulates metabolism. The finding was part of a study published in the Journal of Clinical Investigation (JCI) and British Journal of Nutrition.
In a path-breaking finding, researchers found that consumption of high-calorie diet, which includes fat and sugar, damages the nerves. This, in turn, stops signals through the hypothalamus, thereby obstructing the function of leptin and ghrelin (leptin plays the role of suppressing appetite, ghrelin does the job of increasing appetite). This creates problem for the body as it is unable to regulate weight and metabolism.
The study can help researchers in finding why some people find it impossible to lose weight in spite of serious and repeated attempts to become thin through a series of healthy lifestyle changes like exercise and a balanced diet. The findings can also pave way for new and better weight loss methods.
The finding also coincides with many similar studies which state that each person possesses a unique and natural "set-point" weight, which our body tries hard to maintain. Speaking to reporters about 'set-point' weight, Michael Schwartz, the study's senior author, said, "To explain a biologically elevated body weight 'set-point,' investigators in the field has speculated about the existence of fundamental changes to brain neurocircuits that control energy balance." He further added, "Our findings are the first to offer direct evidence of such a structural change, and they include evidence in humans as well as in mice and rats."
How overeating damages the brain can be best explained in the words of Louis Aronne, obesity expert, doctor and director of the Comprehensive Weight-Control Program at New York-Presbyterian Hospital /Weill Cornell Medical Center. "It's like your gas gauge points to empty all the time, whether or not the tank is full. So you keep stopping for gas, and then eventually you start filling up gas cans and storing them in the back of your car because you're so convinced you could run out of gas at any moment," said Aronne. Louis Aronne believes that though some damage to the hypothalamus may be permanent, a lot of it can be reversed. "Change your diet, and change it fast. If less fatty food comes in, it reduces the rate of damage," explained Aronne.