HKU researcher discovers fat-burning protein that could help treat obesity

A breakthrough involving a University of Hong Kong researcher has isolated a protein that can turn "bad" fat into "good" fat and may one day be used to make drugs that help people lose weight and fight metabolic diseases.

The study, conducted by Dr Roger Wong Hoi-fung in association with the University of California, Berkeley, in the US centres on the difference between white fat, which makes up more than 90 per cent of fat in an adult body, and brown fat, which contains mitochondria, a membrane that burns calories to generate heat.

Brown fat is more common in newborn babies and in people living in colder climes, who need it to keep warm.

The researchers' breakthrough is the discovery of a protein, named Zfp516, which plays a key role in converting white fat into brown. It is found in white fat only when the temperature falls to 15-17 degrees Celsius or lower. Researchers hope to develop drugs to deliver more of the protein, triggering the conversion process and helping weight loss.

"By developing drugs in the future to increase this protein, one could end up with more brown fat without chilling," said Wong, who has worked on the study since 2006. "A female could burn around 600 calories a day without exercising or going on a diet."

In experiments on mice, those with more Zfp516 were found to gain 30 per cent less weight than normal mice when fed on a high-fat diet. When placed in a setting where the temperature was 4 degrees, the mice had temperatures 2 degrees higher than normal mice.

The insulin and glucose tolerance of the mice with more Zfp516 was also reduced.