A zero-calorie drink is a beverage that contains no calories. The two most common examples of zero-calorie drinks are WATER and ice WATER. WATER is a clear, odorless liquid composed of hydrogen and oxygen molecules, and it is essential for life. Ice WATER is simply WATER that has been cooled to a temperature below freezing, resulting in the formation of ice crystals. Both WATER and ice WATER are calorie-free, making them ideal for those looking to reduce their caloric intake.