Looking for help to break the cycle of overeating and under-exercising? Scientists say we need look no further than the brain of the humble roundworm.
At no longer than a millimetre, the transparent worm shares a similar gene to humans. Scientists have found that this gene, located in the brain, controls fat storage in the intestine. It also regulates whether or not the worm feels like having a snooze after eating.
Researchers found that when they removed the gene from a worm, it stored 20-30 per cent more fat in its intestine than a normal roundworm and was more likely to fall into a slumber.
Published in the journal Proceedings of the National Academy of Sciences, the discovery could prompt new treatments for obesity, which is associated with an increased risk of a range of cardiovascular diseases and diabetes.
Two in three Australian adults and one in four children are overweight or obese, according to the Australian Institute of Health and Welfare.
The findings could also prove relevant to treating other eating disorders, according to Roger Pocock from Monash University's Biomedicine Discovery Institute, who led the Australian and Danish research team.
"In removing this gene, you store more fat than you should," Associate Professor Pocock said. "Even when on the same diet."
In understanding the gene, which is regulated by a protein called ETS-5, researchers now have a fresh target for developing new drugs to reduce appetite and increase the desire in humans to exercise.
Associate Professor Pocock said the team also found it could influence worms' fat levels by feeding them a high-glucose diet, which significantly boosted the amount of fat stored in the intestine.
"It was like giving them a can of Coke, basically," he said. "If we provided glucose in their diet they stored much more fat than they would otherwise and they also went into a kind of food coma."
But when sugar was removed from their diet, the worms lost fat and gained energy - much like humans.
The Caenorhabditis elegans worm, which can grow from a single cell to an adult in three days, has more in common with humans than you might think. The two species share up to 80 per cent of their genes. We are also similar in size genetically, with the worm containing 20,000 genes compared with up to 25,000 in humans.
The other advantage of working with the roundworm is the fact that the roundworm remains the only organism to have a complete "neuron connection" map, allowing scientists to understand exactly how the brain is wired.
Associate Professor Pocock said the next step was to use this map to learn how the brain communicates with the intestine; whether it was via the release of a protein or by sending signals to other neurons in the brain before the intestine.
