KEY POINTS:
Scientists are trying to "re-awaken" a human ability lost soon after birth that could help conquer obesity.
Nobel prize winner Sir John Walker, from Cambridge, England, gave an insight into the new frontiers of tackling the global epidemic in a speech to the Queenstown Molecular Biology meeting this week.
The meeting has brought together more than 200 leading scientists in the central Otago town.
With repeated calls for more exercise and less eating failing to stem the obesity epidemic, Professor Walker said the future lay in discovering new drugs or compounds that could fight fat.
Appetite suppressants had been largely ineffective.
"The sort of things we are looking at is trying to activate, or mimic a mechanism that does exist in our bodies genetically whereby we burn off excess energy as heat," Professor Walker told the Herald.
"When we are born, in the first few days of life, we make a protein that does exactly that. It helps newly born children to keep sufficiently warm.
"We rapidly lose that capacity early in life but the gene is there ... so if it could be re-awakened in an appropriate way, then that could be the way of doing it."
Several of the "uncoupling proteins" that caused this process existed in different parts of the body. The process had been shown in users of the drug Ecstasy, which activated one of the proteins.
"Of course, we are not advocating that everybody takes Ecstasy when they are obese but it gives a clue - it's a kind of chemical lead that can be followed up."
A safe drug to re-activate the protein was "not around the corner but it is being pursued".
Dr Robyn Toomath, of the Fight the Obesity Epidemic lobby group, said there would never be a single magic bullet for beating obesity.
A great deal of work was being done to better understand weight gain and a series of drugs could one day treat it effectively.
But drugs currently on the market reduced weight by only 5 to 10 per cent and that was with continued permanent use, Dr Toomath said.
In the meantime, obesity levels in New Zealand continued to climb.
Professor Walker, who works full-time for the Medical Research Council in Great Britain, said there was other work under way to discover chemicals that had the same effect as this uncoupling protein in the body.
A chemical called dinitrophenol, found in explosives, had been shown to be very effective in combating fat but was also toxic.
In some cases, bodybuilders still used it to burn off excess fat before competitions.
