There is, however, some scientific research to back its claims. A 2016 study, published in the Journal Cell Metabolism, tested the effects of a ketone drink on elite level cyclists. Researchers from Oxford University compared the performance of the ketone drinkers to those who had been given a drink containing either fat or carbohydrates. Those on ketones were able to achieve an extra 400 meters (1,312 feet) per half hour and were reportedly less tired and achy post-workout.
The actual idea to create a ketone drink began when the Defense Advanced Research Projects Agency (DARPA) offered scientists millions of dollars in funding to come up with an extremely energy-efficient food soldiers could take into the battlefield. The challenge was accepted by biochemists at Oxford University and the NIH, who went on to invent a ketone ester drink. They call ketones “a fourth type of fuel for humans”.