But, this isn’t what the study said. It just concluded that mostly people of european ancestry have this polymorphism, and it makes them more sensitive to sweetness, meaning that they may use less sugar than someone who doesn’t have this polymorphism.
I think you have to distinguish between sensitivity to sweetness and liking sweetness. Personally, I dislike whole wheat bread because it tastes too sweet to me -- well, not nearly sweet enough for dessert, but sweet enough to ruin anything that's not supposed to be dessert! So I think I'm pretty sensitive to sweet. OTOH, when I do want something sweet, it ain't gonna be whole wheat bread. ;-)