Pointless. You do not need it in the slightest, good quality whole foods are much better, you know what is in it for a start.. Liquids usually absorb quicker than solids on an empty digestive system, however the key word here is EMPTY. Now if you really think that chicken and rice you consumed 2-4 hours ago has been completely digested and all the nutrients used then your a fool. Your body will regulate the speed of its digestive system depending on its needs. So if you eat regular, all that bull shit of when you gulp down your shake 20 minutes later and you got 30-50g of "protein" from your shake fully digested into aminos ready to use is bulls shit. This is still swirling around in your stomach being trickled into your intestines behiind all your other meals. The fact the body cannot store amino acids therefore says something.. protein is used to repair existing cells and create new cells and substances such as hormones. Do you really think that in the time it takes to eat one shake and have another meal your body if it would of not had this would of loss 30-50g of its total mass?
As long as there is something in your intestines being digested that provides more calories than its taking to run your body at that given time your anabolic, if not and your exerting more calories than comming in your catabolic.