Initial increased cravings for sugar and fruits when starting a carnivore diet are an adjustment phase due to dropping insulin and shifting to fat metabolism.

“I think that this is probably I forget the sugar yes the sugar when we're craving sugar clearly that's because it's so valuable nutritionally for us I think that this is an adjustment phase so people are thinking about going on a nose to tail carnivore diet and they experience sugar cravings it's not because sugar is beneficial for you it's not because fruit is nutritious it's because your body's adjusting your insulin is dropping and there's an adjustment phase as you move into ketosis and you change from carbohydrate based metabolism to fat based metabolism”