Can a 4 year old drink whey protein shake?

Children may take protein shakes at any age, keeping in mind that the daily requirement for protein is only about 50-75 grams. Eating more protein than the body needs at any age will not increase muscle mass, it will only add calories and be stored as fat. Also consider that many of these protein sources , while providing adequate nitrogen, if taken to the exclusion of normal meals may result in a lack of vitamins, minerals and trace elements found in "whole" foods.