[austinjp]

Can you define what you mean by a serving? If the percentage of sugars is lower in skimmed milk (or full, whichever) then that will most likely raise blood glucose least, no?

There's also the personal factor to consider. Everyone has a unique metabolism. The only way to be sure is to take your fasted blood glucose levels then monitor your response after consuming a serving of a single food item. That food may raise one person's blood glucose more/faster than someone else's. Fortunately it's relatively easy to do this today for many people, although price and availability are variable.