Hmm
This would be an interesting topic, but I believe we all have diffrient digestive rates, and various condtions will effect this. If you just lifted, did cardio, just ate a large meal and ate again, had no carbs in the system and ate.
I think I read about how liquid meals digest in about 1-2 hours, and most whole food meals take about 2-3 hours. SImple sugars enter the blood stream real quick, complex carbs will be slower, depending on fiber. Fiber/fats will slow digetstion way do, just like adding some protein can do the same thing.