I’m now using an automated insulin dosing system that takes care of fat/protein dosing. For several years I did dose explicitly for carbs, fat and protein.
Here’s what I did but please do your own experimenting to discover what works for you. All of this dosing is premised on a carb-limited diet. I eat about 60 grams of carbs per day or less. Most meals are limited to less than 20 grams of carbs. The reason I say this is that insulin dosing for protein needs to take place in a carb limited environment. A person eating an abundance of carbs will not need to convert protein to glucose and will therefore not need a protein insulin dose.
In addition to the usual carb bolus, what I did was add 50% of the protein grams and 10% of the fat grams to get a total that I called carbohydrate equivalents. I then treated this number like a carb for calculation purposes.
I divided this carb equivalent total by my insulin to carb ratio to arrive at a total insulin dose for fat/protein. I delivered this fat/protein equivalent carb dose as an extended pump bolus at the maximum hourly rate of 1.2 units per hour. You will need to confirm this by your own personal experimentation. This is what worked for me.
For example, let’s say I wanted to eat a meal with 60 grams of protein and 50 grams of fat, I would calculate the equivalent carbs by taking 50% of the protein grams and adding it to 10% of the fat grams. In this case (60 grams x 50%) + (50 grams x 10%) = 30 + 5 = 35. If you have an insulin to carb ratio of 1:7 then divide 35 by 7 which equals 5.
So, if you limit the extended bolus to 1.2 units per hour, you would deliver 5 units over 4.5 hours or about 1.1 units/hour.
I am not saying that this is a formula that will work for you. I am not a doctor or dietitian. You can use this, however, as a basis to begin your own experimentation.