Well, just because SodaStream uses real sugar in the place of the commonly-used high-fructose corn syrup in their sodas, doesn't mean you're drinking something natural. The lower calorie totals in
That means very few calories. Less than one, I assume. Coke zero does not have zero calories, but in nutritional information labelling, there is threshold below which you can round down, and if the nearest number is zero, you can round down to 0 and say zero calories. Same with trans fats, etc.
Some soda made without high fructose corn syrup manufactured by Pepsico are: Pepsi Natural an all natural cola sweetened with natural sugar and nothing artificial. Ingredients: sparkling water, sugar, natural apple extract (color), caramel color, citric acid, caffeine, acacia gum, tartaric acid, lactic acid, natural flavor, kola nut extract.
The target response is that, assuming equal molar quantities of each sweetener, the mass ratio of sweetener would be 294/180 aspartame : high fructose corn syrup (HFCS), meaning the Diet Coke would actually contain more sweetener mass. Under such a scenario, the Diet Coke can should be more dense than the Coke can, which is contrary to observation.
PPTV.