We put them to the test by baking cakes.

There are plenty of reasons to avoid fructose (a.k.a. sugar, the subject of the cover story in this month's issue of National Geographic magazine) and its even more vilified twin, high-fructose corn syrup.

For athletes, these sweeteners provide much-needed energy. For the rest of us, they're high-calorie, zero-nutrition temptations that can lead to obesity and a host of related conditions