If this "takes", all endurance pro athletes will be forced to eat stuff that Dr. Attia describes by saying "the world’s worst scotch tastes like spring water compared to these things", by the spoonful, continuously while competing, pretty much the way we eat gels, in order to be competitive. And it seems likely that effects scale with dosage. You can get what looks like 6-8% improvement in work per unit of oxygen from a 15 g dose, but, logically, you'll get more from 30 g, etc. etc. till you're running 100% on ketones. And there's still the problem that this stuff gets metabolized into acetone. A single 15 g dose before a 20 min bike ride may not have any lasting effects, but try to eat it as you eat gels over the course of a 5 hour bike race, and that may be an altogether different story.
My guess is, if ketones really work as described and if/when they go widespread, food or not, they'll be classified as doping.