Jimpsull: Outside of some protein, there's little nutrition in egg white. In addition (the following is assembled from 2 sources); Biotin is an important component of enzymes in the body that break down certain substances like fats, carbohydrates, and others. Raw egg white contains a substance called avidin that binds biotin in the intestine and keeps it from being absorbed. Eating 2 or more uncooked egg whites daily for several months has caused biotin deficiency that is serious enough to produce symptoms. Cooking the whites can deactivate the avidin, but also deactivate a lot of the protein in the whites. The nutrition's in the yolk.