US scientists have discovered a protein that prevents the body burning fat, which could be the key to reducing obesity.
The TRIP-Br2 protein regulates the way fat is stored and released from cells.
When University of Florida researchers compared mice who did not have the gene responsible for TRIP-Br2 production with mice that had the gene, they found the mice that lacked the protein did not gain weight and remained healthy, even when fed a high-fat diet.
However the group who had the protein and were fed an identical high-fat diet gained weight and developed insulin resistance, high cholesterol and type-two diabetes.
"We had to explain why the animals eating so much fat were remaining lean and not getting high cholesterol. Where was this fat going?" said study author Dr Stephen Hsu.
"It turns out this protein is a master regulator. It coordinates expression of a lot of genes and controls the release of the fuel form of fat and how it is metabolised."
TRIP-Br2 limits the amount of fat that cells can burn as energy. But when it's absent, fat cells go into overdrive, burning free fatty acids, which, among other things, increase heat in the body, which the researchers say protects us from exposure to cold.
Now the researchers hope drugs can be developed to trick the body into thinking the TRIP-Br2 protein is absent.
"We showed that only human subjects who had the kind of fat that becomes insulin-resistant also had high protein levels of TRIP-Br2," Dr Hsu said.
"Imagine you are able to develop drugs that pharmacologically mimic the complete absence of TRIP-Br2."
It would work by helping people burn off their existing fat stores.
"If people are at risk of obesity and its associated conditions, such as type 2 diabetes, it would help keep them lean regardless of how much fat they ate," Dr Hsu said.
"That is the ideal anti-obesity drug, one that prevents obesity and helps people burn off excess weight."
Further studies will be undertaken on animals before human trials are undertaken.
Joseph Proietto, professor of medicine at the University of Melbourne and head of the obesity clinic at Austin Health, told MSN the findings are interesting but probably don't hold the solution to fixing obesity.
"These people have discovered a protein, which we call a transcriptional regulator. It's a protein that's inside cells that controls the expression of multiple genes," he said.
"What they found is when they remove this protein, as they did in mice, the mice seem to have burnt off fat. It's very interesting and it's a good advance, but we will need to a lot more studies in animals and humans if they are able to develop an inhibitor of TRIP-Br2."
Professor Proietto's biggest concern was that a drug that suppresses TRIP-Br2 will increase heat in human bodies.
"In exercise you increase fat burn because you need the energy," he said.
"If you do it from sitting and you are increasing your energy expenditure, all you do is get hot. This could be a potential problem if it causes fevers and causes the body to become too hot."
The research was published in the journal Nature Medicine.