But there’s a catch: Professor Febbraio is not holding out the possibility of a knockout slimming pill that would decimate the ranks of the seriously overweight in countries like Australia and the United States.

He expects that a course of interleukin 6 would only ever be an adjunct therapy to a fitness regimen and healthy eating.

"If people exercised and had a proper diet, I’d be out of a job," Professor Febbraio admitted. "The best therapy to avoid obesity and type-two diabetes is to do daily exercise."

In fact, the real breakthrough at RMIT’s Skeletal Muscle Research Laboratory is in discovering the strength of the link between weight loss and activity. It came about when Febbraio’s team tested blood samples from marathon runners.

The team found that the appearance of interleukin 6 in the plasma was increased 120-fold by running 42 kilometers.

"The popular theory was that the immune cells were making this protein to protect the body from infection following exercise," Febbraio said. "But when we looked at this we found the immune cells actually decreased their production. We asked ourselves where the protein was coming from and that’s where we made the marked finding that it’s the muscle cells that make them."

They took isolated fat cells and isolated muscle cells and treated them with interleukin 6. They found the rate of fat breakdown in the fat cells increased and the rate of fat uptake in the muscle cells increased.

What was happening was that the body was releasing interleukin 6 during exercise and the protein was triggering the release of glucose and fat. Interleukin 6 was breaking down fat in adipose tissue and increasing the use of fat in the rest of the body.

The RMIT research program was begun after findings elsewhere that fat mice injected with interleukin 6 rapidly slimmed down.