That's not true. Last podcast I heard with Dom he said of course calories matter (and he didn't add "except on keto"). Bikman said sth similar on one of his latest Reels... Hardly any scientists one can take seriosuly claims calories are somewhat irrelevant on a keto / high-fat / low-carb diet. Only guys who sell diet books or programs.... I don't know if someone truly believes that you can eat all you want from any food any not gain weight. But there are enough people who have fallen for this marketing trick and got disappointed.

Your water analogy btw is utterly useless. It says just as much about human physiology as rat studies... .