Isn't this sorta obvious? I always assumed the calorie counts in foods were old data, calculated a century ago, and the foods labeled with those counts have been so modified since then that they are little more than relative guesses useful for moderate comparison only. Add in the variances of how different people digest, as well as how food combining impacts digestion, and those counts are marginally useful at best. "Calorie" in foods have little to nothing to do with "calorie" in chemistry and physics, other than they were originally intended to be the same, but any thinking individual directing attention to them sees they are not.