I think this has turned into an absurd and pointless discussion.
goal245 shared his experience with the carnivore diet and extended fasting.
Hawkmoon countered by saying that fasting is starvation, and therefore can leads to muscle catabolism.
The carnivore diet can be useful for bodybuilding, just like the ketogenic diet, just like a high-carb diet. Badboy has experimented with the sugar diet, but for years he has used a keto diet even though almost everyone claims you need carbs to build massive muscle mass as a pro bodybuilder.
In any case, goal245 never said that the carnivore diet was the best option if you want to be a bodybuilder with massive muscle mass.
Regarding fasting, you won’t lose muscle mass if you fast for 72 hours, provided that:
1. You aren’t at a body fat close to contest shape —that is, if you’re at 10–12%, which is recommended or habitual during the off-season.
2. You have trained and followed your usual diet for 3–4 days before starting the fasting period. For example: you train on Wednesday your last train, then rest and continue eating your usual diet until Sunday, and fast from Monday.
If you train out and break down muscle and then fast, you’re likely to lose muscle mass. But if you do what I say and are also a on gear athlete, thinking you’re going to lose muscle mass it could say that you're being overly paranoid and not thinking rationally.
The benefits of fasting are backed by centuries of practice by countless sages and ascetics throughout history. Of course, these people weren’t concerned with building muscle mass, but we should still recognize the importance of such fasting, just as you've discussed the importance of meditation here.
Fasting is not an effective method for losing fat, and I don’t think goal245 ever claimed it was—correct me if I’m wrong. He’s recommending fasting for other reasons, but it’s certainly good for your health to give your digestive system a break.