Discovery of fat 'switch' fuels hopes of a cure for obesity
Scientists have discovered the precise brain mechanism that causes the body to hold onto fat, raising hopes of a cure for obesity.
For the first time, lab trials have explained how the brain's ability to sense insulin in the body, levels of which are raised after a meal, is co-ordinated with expending or conserving energy.
Researchers at Monash University in Australia have described the findings as "very exciting", and said that they highlight targets for potential fat-inhibiting medicines for people who cannot help putting on weight.
Fat in the human body is stored in specialised cells called adipocytes.
These can change from white when in storage mode, to brown when expending energy, and back again.
In healthy people, the mechanism responds to high levels of insulin in the blood by "browning" the fat, and to low levels, such as after a fast, by keeping the fat white.
For obese people, the "switch" stays on all the time, the researchers 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," said Dr Garron Dodd, first author on the study, which is published in the journal 'Cell Metabolism'.
"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."
Previous investigations by the researchers, that showed how the brain co-ordinates white adipose tissue browning, attracted considerable attention after they were published in early 2015.
"For a long time, the missing piece to the puzzle was always why this occurs in the body," said Dr Dodd.
"We've shown not only why this occurs but also the fundamental mechanism involved. It's very exciting," he added.
The researchers are further exploring the possibility of inhibiting the switch for therapeutic purposes in order to promote the shedding of excess fat.
But they warned that safe therapies are a "long way off".
In England, the NHS currently spends more than £1bn (€1.1bn) a year treating diseases which are fuelled by obesity, new research revealed in May.