London: Scientists claim to have finally revealed why scoffing junk food actually makes one eat more --it destroys the brain`s ability to control one`s appetite.
A new study has found that fatty food destroys the brain cells that control weight, leading to a vicious circle of obesity, a finding which may explain why it`s so hard for fat people to shift the pounds, the `Daily Mail` reported.
For their study, the scientists fed rats what they described as a "typical high-fat American diet" and found they had doubled their calorie intake three days later.
Further study showed they also had an inflammation in hypothalamus, the part of brain containing neurons that control body weight. This inflammation stopped a few days later but then recurred after four weeks.
Lead researcher Dr Joshua Thaler at the University of Washington in Seattle, said that they also detected a healing response to brain injury called gliosis. "Gliosis is thought to be the brain equivalent of wound healing and is typically seen in conditions of neuronal injury, such as stroke.
"We speculate that the early gliosis that we saw may be protective response that fails over time. We also detected damage to and eventual loss of critical weight-regulating neurons," he said.
Dr Thaler added: "The possibility that brain injury may be a consequence of the over consumption of a typical American diet offers a new explanation for why sustained weight loss is so difficult for most obese to achieve.
"It is not yet clear whether this presumed neuronal injury is permanent, but it may contribute to weight gain. If medicines can be designed that limit neuron injury during over-eating they may be effective in combating obesity epidemic."
The findings have been recently presented at the Endocrine Society`s 93rd annual meeting in Boston.