The holidays are a glitzy, festive time, but health officials are warning Americans to think twice before using glitter to add a sparkly touch to their holiday baking.In a consumer update , the Food & Drug Administration offered guidelines to help bakers determine exactly which types of glitter are edible and which are better left for craft projects.Because it's technically a food product, edible glitter is legally required to include a list of ingredients. According to the FDA, edible glitter often includes the following ingredients: sugar, acacia (gum arabic), maltodextrin, cornstarch and color additives.Additionally, edible glitter should be clearly labeled as such. Phrases like "non-toxic" or "for decorative purposes only" do not indicate that something is edible, the agency warned.Glitter products, both those that are edible and those that are not, could be marketed as "luster dust, disco dust, twinkle dust, sparkle dust, highlighter, shimmer powder, pearl dust and petal dust."