Scientists have accidentally found a way to create a pill that would let you eat excessive amounts of fat without gaining weight.
The team at Yale University were trying to cultivate a batch of morbidly obese mice.
However, in doing so they edited out two genes - which, in turn, appeared to protect the mice from weight gain, despite living on a high-fat diet.
While they have so far only tested this on rodents, the researchers believe they may be able to target those same receptors in humans, to block fat from being absorbed into the gut.
The team, led by cardiology professor Anne Eichmann and associate research scientist Feng Zang, had made many tweaks to the genetic make-up of their lab mice to make them pile on pounds.
But as the weeks went by and the rodents stayed slim, they decided to pause and investigate.
They found that two genes in particular had caused a unique and crucial change in the gut: it had flattened certain 'portals' called lacteals.
These portals act as the gateway for lipids (fatty acids) to either move into the blood stream for energy, or be stored as fat.
Until now, however, it wasn't clear how crucial they were; that 'zippering up' the lacteals could prevent weight gain altogether.
The 'failure', reported in the latest edition of the journal Science, paved the way to an entirely different prospect: could the same be done in humans?
It could not, for obvious ethical reasons. But rather than editing our genes, perhaps there is a way to inhibit certain receptors that would trigger the same lacteal-flattening effect.
As it happens, they found, there is a drug that performs that purpose. It already exists, and it is approved by the US Food and Drug Administration to treat glaucoma, the leading cause of blindness.
The drug inhibits the Rho kinase ROCK, a set of molecules that hold the puppet strings for the lacteals.
Dr Eichmann said the next step could be to monitor patients who use this drug, to see how it impacts lipid uptake and weight gain in humans.