The foundation of any good diet to make “gains” (build muscle mass) is high quality complex carbohydrates. I.E. oatmeal, sweat potatoes, yams, pumpkins, squash, brown rice, rice. Notice a starch that I left out? Corn. Corn in an unprocessed form is virtual indigestible by humans.
Dymatize Elite Mass High-protein muscle gainer primary carbohydrate source is Maltodextrin. *“Maltodextrin can be enzymatically derived from any starch. In the US, this starch is usually corn” This product’s Supplement Facts list 75g of Total Carbohydrate 8g as Sugars. Maltodextrin a heavily processed corn product that while technical not a sugar it is processed very similar to sugar. *“Maltodextrin is easily digestible, being absorbed as rapidly as glucose”.
Taking Dymatize Elite Mass High-protein muscle gainer before your work out is going to cause a sharp insulin response during your work out which is not what you want. This product is meant to be taken after a workout not before.
To answer your question about “what else should I consume to maximize my gains?”
Consume high quality complex carbohydrates early in the day before
you work out
Avoid all easily digestible Carbohydrates (sugur, Maltodextrin,
Maltose, corn surup) before your work out.