In a breakthrough scientists in the US have discovered a hormone that regulates hunger and may help to fully control appetite in the future.
Researchers at Stanford University, California, looked at gene sequences in humans and animals, including one that codes for ghrelin, an appetite-boosting hormone.
They found another hormone, 'obestatin', was processed from the same protein precursor that produced ghrelin. The researchers say obestatin was found to suppress appetite - the opposite effect to ghrelin.
When they gave injections of obestatin in the abdomens and brains of rats they found that the rats ate about half as much as those who were not given the hormone. They also put on less weight, the online edition of BBC News reported.
The researchers found that obestatin also slowed the movement of food from the stomach to the intestines.
Professor Steve Bloom, an expert in obesity research at Imperial College, London, said the research was fascinating.
"It points to another part of the complex appetite-regulating system that we could affect using a drug," he said.
Bloom said it added to other discoveries about how hunger is regulated. "We should be able to control appetite within five to 10 years."
But the fact that an appetite-suppressing hormone is made by the same cell as an appetite boosting one was "a bit of a puzzle", he said.