I would say aim for 30g carbs and about 73g fat on off days.
For your training days keep everything the same - simply have your workout nutrition on top of it all to keep things simple.
I am of course assuming you are going to try a keto approach.
The way I worked this out was:
Work out the non protein calories
Allow for 30g of carbs and take off total calories left
Work out how many grams of fat for 660 calories:
Now this is a rough guide and it will depend on your macro split.
You could even try with a much lower daily carb intake with the exception of your workout days when you have your Surge…