fructose is sweeter than either sucrose
"fructose is sweeter than either sucrose (table sugar) or glucose and has different physical effects. It does not stimulate insulin secretion, which is related to people feeling full, but does stimulate the formation of fat cells. Bray (George) found that the rise in use of corn syrup paralleled almost exactly declining intake of milk and rising prevalence of obesity."
Source: Brownell, Kelly D and Horgen, Katherine Battle, Food Fight, 30