A doctor advised me to always include a fat source if eating something with carbs. He said it was fat, not protein, that would best slow down the carb absorption. Also it's possible to see a change in blood sugar (possibly higher) when eating protein without any carbohydrate. If I understand it correctly, this is because protein triggers insulin release. Not as much as carbs, but some in order to process the protein. So the liver, to avoid blood sugar dropping dangerously low, releases glucose from stored glycogen. So a higher glucose reading could possibly result, but it would be from the body's own released glucose stores rather than carbohydrate consumption.