High levels of fatty acids, or lipids, in the reptiles' blood nearly doubles the sizes of their hearts and other organs after breaking a long fast, experiments show.

The organs of pythons, which are infrequent eaters, balloon to speed up digestion after a typically enormous meal, according to study co-author Leslie Leinwand, a molecular biologist at the University of Colorado at Boulder.

Until now it’s been a scientific mystery how the python's body accomplishes this "extraordinary" feat, Leinwand said.

"When we drew blood from the animals, we figured that whatever what causing this organ growth was in the circulation, because all the organs, except the brain, had a post-meal increase in size."

And "when we looked at [the blood], it was