Why does the 20 oz Diet Mt Dew say it has 10 calories in it?

The reason for the 10 calories reported on the 20 oz Diet Mt Dew is because of the concentrated Orange Juice that is used in Dew.

The calories are not listed on the 12 oz can because there are less than 5 calories, which is the minimum amount of calories required by the FDA to be reported on a food label.

There are 4 calories in a 12 oz of Diet Mt Dew, so by consuming 20 oz of Diet Mt Dew one would be consuming 10 calories.