Just out of interest. What is the reason you would like to eliminate carbs from the shake?
Would it not make sense as a diabetic to take a carb supplement with your protein shake and a few units of insulin to counter the carbs? The insulin worked out according to your carb to insulin ratio and the carb supplement weighed/measured exactly and tested carefully. Insulin is after all an anabolic hormone an is required to build muscle. Something like this:Maxi Carbs 1kg sksports powder