This is good advice. I know there are a lot of carnivores on here who think they're allergic to sugar. People are doing intermittent fasting and only eating meat for dinner.
I did that, lost a lot of weight. Problem is, it takes willpower and you'll get rundown and sick after a while. When/if you take a break, your metabolism is fucked and you'll bounce back/regain all the fat you lost.
Sugar in and of itself is not bad. Do some research. Look into Kempner's rice diet. Does your keto/carnivore influencer ever explain that?
Fat melts off of you on a water fast because your cortisol and adrenaline are running high. It isn't good for you. Sugar suppresses cortisol.