>I have in my hands a cup of fruit yogurt (empty as I already consumed it).
>
>The sugar content of this cup is 18 g. But I would like to see how many grams of the sugar comes from the fruit and how much is the processed sugar. I am thinking about writing to my congressman.

It does not matter that much if the carbohydrate is added sugar, "natural" sugar or even if it is some kind of starch.

Well, fructose (fruit sugar) is suspected of being a liver poison and causing non-alcoholic fatty liver disease and even diabetes, so the added sugar may be less dangerous than the natural sugar.

What matters is how much carbohydrate and how fast the carbohydrate turns to glucose (the only kind of sugar in your blood)
White bread turns to glucose rapidly and hits your bloodstream faster than cotton candy, so the idea of "complex carbohydrates" is not that useful.

The starch in white bread (all bread really) is a chain of glucose molecules that breaks apart to glucose as your saliva hits it. Table sugar is half glucose (instantly absorbed) and half sucrose - requires a trip through the liver to convert sucrose to glucose so it takes longer to hit your bloodstream.

wwwGlycemicIndex.com