I feel thats very subjective to every person due to different digestion speeds, but its all about knowing how your body will react do different food, drinks (mostly coffee) and physical activity. Eating portions that will basically go out in one go, while the next one is far enough up and sold enough to give you time. Normal pasta with cheese gets me good results. Like if you had your last meal around 18:00 last day, get a full night of sleep, have some coffee, do a little sport, get it all out at lets say at 10:00, then have the next meal of pasta…you got yourself a 8h time slot for fun.