Scientists are linking obesity with inflammation and scarring in the key brain area that controls weight, which could explain why it’s so hard to lose weight and keep it off.

When researchers switched mice and rats genetically bred to become obese from low-fat chow to high-fat and highly palatable chow, they began showing signs of inflammation in the hypothalamus within 24 hours.

The hypothalamus takes signals from body fat and other tissues that tell the brain we need food or we’ve had enough. It also regulates how much fat we burn.

“We saw direct evidence of neuron injury and, ultimately, after months on the diet, a loss of neurons in this hypothalamic area that’s vital for body weight control,” said lead researcher Dr. Michael Schwartz, professor of medicine and director of the Diabetes and Obesity Center of Excellence at the University of Washington, Seattle.

The switch to the high-fat diet “is actually injuring the neurons that are supposed to protect them from obesity,” he said.

Brain scarring may help explain obesity battle, study finds

While shift workers are needed to help our 24-7 world go ’round, an editorial written by Dr. Virginia Barbour, chief editor of the journal PLoS Medicine, warned that such work schedules can put a person at increased risk of obesity and type 2 diabetes. She even argued that unhealthy eating habits on the job should be considered an occupational health hazard.

“We have a long-standing interest in publishing on the diseases and risk factors that cause the highest burden of disease,” Barbour told ABCNews.com.

“We would suggest that employers need to take unhealthy eating very seriously, to the extent that they consider that unhealthy foods are essentially environmental hazards and that they should consider what the implications are of exposing their employees to high levels of such hazards in the form of vending machines and fast-food restaurants.”

Shift Work Might Lead to Type 2 Diabetes, Obesity

The Washington state ferry service isnt going to start turning away hefty passengers, but it has had to reduce the capacity of the nations largest ferry system because people have been packing on the pounds.

Coast Guard vessel stability rules that took effect nationwide Dec. 1 raised the estimated weight of the average adult passenger to 185 pounds from the previous 160 pounds, based on population information from the Centers for Disease Control and Prevention.

Obesity Rise Prompts Wash. Ferry Capacity Change – ABC News