MELBOURNE, Aug. 2 (Xinhua) -- A "switch" in the brain that regulates fat-burning could be a key reason as to why obese people struggle to lose weight, an Australian study published on Wednesday has found.
The research, released by Monash University in the Cell Metabolism journal, discovered that the brain usually signals the body to begin browning fat to burn energy when insulin levels are high, usually after a meal.
Tony Tiganis, lead author of the study, said that the brain's ability to detect insulin levels and coordinate the browning of fat is controlled by a mechanism similar to a switch.
"What happens in the context of obesity is that the switch stays on all the time -- it doesn't turn off during feeding," Tiganis said in a media release.
"As a consequence, browning is turned off all the time and energy expenditure is decreased all the time, so when you eat, you don't see a commensurate increase in energy expenditure and that promotes weight gain."
Fat-browning is the process whereby white fat, which stores energy, turns into brown fat which burns energy.
In contrast to high insulin levels, the brain instructs the body to convert the brown cells back to white cells in order to conserve as much energy as possible.
The process, when functioning normally, is key to preventing the body from gaining, or losing, too much weight.
Researchers described the discovery of the process as a major moment in the fight to better understand, and fight obesity.
"Obesity is a major and leading factor in overall disease burden worldwide and is poised, for the first time in modern history, to lead to falls in overall life expectancy," Tiganis said.
"What our studies have shown is that there is a fundamental mechanism at play that normally ensures that energy expenditure is matched with energy intake.
"When this is defective, you put on more weight. Potentially we may be able to rewire this mechanism to promote energy expenditure and weight loss in obese individuals. But any potential therapy is a long way off."
