Question about Vitamin Water Zero

[Free4Life11]

I bought a bottle of the "mega-C" Vitamin Water Zero and the nutrition facts state 4 grams of carbohydraters per serving, but no calories. How can this be? I though 1 carbohydrate = 4 calories, so that would be 16 calories per serving. There are 2.5 servings in a bottle so that would be 40 calories per bottle. Can anyone solve this mystery for me? Thanks.

 

[Muggle-born]

I bought a bottle of the "mega-C" Vitamin Water Zero and the nutrition facts state 4 grams of carbohydraters per serving, but no calories. How can this be? I though 1 carbohydrate = 4 calories, so that would be 16 calories per serving. There are 2.5 servings in a bottle so that would be 40 calories per bottle. Can anyone solve this mystery for me? Thanks.

My only guess is that it's a very genetically and/or chemically modified carbohydrate that is 0 calories. Or, if anything, it's a carb that is modified to a very small amount of calories... they only have to put rounded out numbers.