Chocolate milk is a type of flavoured milk made by mixing cocoa solids with milk (either dairy or plant-based). It is a food pairing in which the milk's mouthfeel masks the dietary fibres of the cocoa solids. Sugar used in commercial chocolate milk are used as preservative, and the energy from the sugar also makes it a convenience food. It can also be made at home by blending milk with cocoa powder and a sweetener (such as sugar or a sugar substitute), melted chocolate, chocolate syrup, or a pre-made powdered chocolate milk mix. Other ingredients, such as starch, salt, carrageenan, vanilla, or artificial flavoring are sometimes added. To add nutritional value to the product, sometimes some minerals like zinc oxide or iron are added. In New York City, school food officials report that nearly 60 percent of the 100 million cartons served each year contain fat-free chocolate milk.