Heath food are not good on mages. Because it Shares cooldown with the Mana foods aswell.
the Best foods to use in a Mage are
1.Blueberry Cupcake - fill your mana (doesnt share cooldown with "Blessed steak" food
2.Blessed Steak - Fills your mana (doesnt share cooldown with "blueberry cupcake" food.
So you can use these foods at the same time with your mana shield potion, since mages dont tank that much after the mana shield update.
hope it helps!