Rock candy is a crystallized product of granulated sugar, named because it crystallizes like ice. The main ingredient of rock candy is glucose containing water of crystallization. As a food, rock candy has a certain role in replenishing energy for the body. Because the main ingredient of rock candy is glucose containing water of crystallization, so every 100g of rock candy contains 99.3g of carbohydrates, a large number of carbohydrates in rock candy can provide the body with enough heat energy, so that the blood glucose rises rapidly, and can be used to alleviate the symptoms of hypoglycemia. Icing sugar also contains some calcium, potassium, sodium, iron, zinc, copper and other minerals, has the role of supplementing a variety of nutrients for the body. However, it should be noted that icing sugar should not be eaten too much, easy to caries. Patients suffering from diabetes, high blood sugar should also be cautious under the guidance of a medical professional.