That's the claim:
After humans and rodents eat a high-fat diet, their brains begin to show evidence of injuries in just 24 hours. If they keep eating that yummy fatty stuff continuously, the area of their brains that regulates weight — the hypothalamus — will show evidence of serious inflammation and structural damage.[...]
That may help explain, researchers said, why dieting and exercise often lead right back to a "set weight" for obese individuals.
"Obese individuals are biologically defending their elevated body weight," said Dr. Michael Schwartz, a professor of medicine at the University of Washington and the senior author of the paper to be published in the Jan. 3 edition of The Journal of Clinical Investigation.
Eager to explain why that set point seems to exert so much control over a person's weight, Schwartz said, numerous researchers have speculated about the existence of "fundamental changes" to brain neurocircuits that control energy balance.[...]
Schwartz said the findings show "solid evidence of a change affecting the key hypothalamic area for body weight control with the potential to explain the problem."[...] "We did not prove cause and effect between the hypothalamic neuron injury and defense of elevated body weight — that comes next," Schwartz said.