I don't think all react the same. Popular thinking would tell you it's due to the lack of fiber but I don't see it as problem anyway. Think Rogan said he had it for the first 2 weeks and said next time he does carnivore, he'll include meat and fruits... which doesn't sound very carnivore.
Guess rogan is keto carnivore with da fruits i suppose. guess it comes down to what version of carnivore ppl are doing dependant upon their goals. some peeps just want all animal products, some restrict themselves to beef, salt n water and no carbs etc.
when i did keto.. i ate meats, but its focus wasnt heavy.. got my fats n protein in various way... but i would add fiber rich complex carbs trying to offset the carb totals.. i didnt eat meat some days, maybe just a lot of eggs with various fatty oils to raise me fats/cals
technically ive been doing keto carnivore nowz.. there are minimal carbs in cheese and there are possible minimal carbs in mince via fillers used in the manufacturing of said beef mince. i could mince me own if i cared that much about it..
chicken days are close to 0 carb.. with cracked pepper not anymore.. so maybe im hovering around 0.1-2g of carbs per day. in me head it might as well be 0, but in reality its not.. i dont think zero carb will be the goal.. i like mince.. and i like pepper to balance me salts, 3even though my salting is heavier now and there is no balance.. plus i will introduce various other spices in the future as well.. i can go without cheese or find even lower carb/sugar cheeses... but im carnivore focused