Eating a high-fat diet even for a short period may change the brain in ways that makes it harder to lose weight, a new study has found.
In experiments on rodents, a team at the University of Washington School of Medicine found that when placed on a high-fat diet, the animals developed injuries to a brain area called hypothalamus that controls the urge to eat and sends signals to stop eating when full. Signs of similar damage in the same brain area in obese people have also been found, the researcher said.
“Within 24 hours of switching rodents to a high-fat diet, we found injury in the hypothalamus area,” study co-author Dr Michael Schwartz, an endocrinologist at the University, was quoted as saying by LiveScience.
According to the researchers, obesity causes inflammation in the tissues and organs. This isn’t the same type of inflammation you get during an allergic reaction. Instead it’s a low level of inflammation that persists in the body.
Researchers speculated that obesity might also be linked with inflammation in the hypothalamus, “which may prevent it from responding to hormones like insulin that regulate our body weight,” said co-author Dr Joshua Thaler. Researchers compared rats and mice that ate a high-fat diet with those that ate a regular diet over a four-week period. Within the first week, they found gliosis — an overgrowth of cells that is a sign that the brain has tried to heal itself. They also found that though the brain’s repair effort was effective, inflammation and gliosis persisted as long as the animals remained on a high-fat diet.