GlucoseDespite its absolute necessity for life (see chapter 10), dietary glucose isn’t perfect. When it exists in nature without fructose, it’s called “starch,” and it truly does supply “empty calories,” energy for either storage or burning.
FructoseFructose is never found alone in nature. Rather, it is always partnered with its more benign sister molecule, glucose.
Robert Lustig, Fat Chancep.154, 156