This is pure speculative thought, but I feel the crux of the problem may be in the tests to determine the caloric load of foods/drinks - they literally just set it on fire, with the fundamental reason being, this is more or less how our body draws energy from what we consume. I could be wrong, but I feel as though my insides constitute something much more intricate and complicated than a furnace. As I see it, the problem lies in our methods of determining the respective energy potential/composition of a given food - the problem may be with the standard of measure, not a method of dietary restriction.