An experimental drug has been found to speed up metabolism and burn off fat cells, according to a study conducted on hundreds of mice by the Houston Methodist Research Institute, US.

Dubbed ‘GC-1’, the drug works by activating the receptors for thyroid hormone, which play a role in regulating the metabolism – the body’s conversion of food into energy.

“CG-1 dramatically increases the metabolic rate, essentially converting white fat, which stores excess calories and is associated with obesity and metabolic disease, into a fat like calorie-burning brown fat,” said the study’s author Kevin Phillips PhD.

Until several years ago, scientists thought that only animals and human infants had energy-burning “good” brown fat.

“It is now clear,” said Phillips, “that human adults do have brown fat, but it appears to lose its calorie-burning capacity over time.”

White adipose tissue, or fat, becomes a “metabolic villain” when the body has too much of it, according to Phillips. People with more brown fat have a reduced risk of obesity and diabetes, thus researchers are now working on ways to convert white fat into brown fat.

Phillips and other researchers tested the drug on hundreds of mice, with partial funding from the National Institutes of Health, according to ScienceDaily. Both genetically obese mice and those with diet-induced obesity received GC-1 treatment daily.

The genetically obese mice lost weight and more than 50 per cent of their fat mass in approximately two weeks, according to Phillips. The treated mice also showed anti-diabetic effects, such as a six-fold improvement or better insulin sensitivity – how well the body clears glucose from the bloodstream. Mice with diet-induced obesity experienced similar improvements, said Phillips.

“Our data demonstrate that GC-1 is a novel fat-browning agent that may have a use in the treatment of obesity and metabolic disease,” added Phillips.

While the drug has not yet undergone testing for weight loss in humans, GC-1 is being tested in clinical trials for lowering cholesterol under the name sobetirome. Phillips said, however, that the doses of sobetirome used in cholesterol-lowering trials are much lower than what would be needed for weight loss.

A recent study found that obese people have fewer ‘pleasure receptors’ in their brains, which could explain their need to overeat.