Granulated fructose (fruit sugar) a natural by-product of fruits and honey. Fructose loses some of its sweetness when heated so some adjustments may be needed when substituting for granulated sugar. Fructose contains half the calories of granulated sugar. Fructose is roughly 50% sweeter than ordinary sugar. In general, if a recipe calls for 1 cup of sugar, use a little over a 1/2 of a cup of fructose, sweetening to taste.