[ra88it]

Keto community generally recommends replacing carbs with fat and keeping protein constant. Protein consumption is almost a constant (with some variability due to workout regimen, etc).

I think of it like a see-saw, with protein level being the axis of rotation (ie., it stays the same). Now you have 2 remaining macro variables: carbs and fat. If you decrease one, you need to increase the other or else caloric intake might be too low.

Keto community generally refers to the diet as Low Carb High Fat because not eating enough fat can cause problems on the diet.

Edit: To be clear, assuming sufficient consumption of protein, if calories are still deficient, keto community recommends making up the deficit with fat rather than protein.