Is it true that if you take the same food, same amount and everything except one serving is heated and another is not. Would the person eating the heated serving get more nutritional value from it in the form of more energy? This comes about from the larger potential energy stored in the bonds of the food that has been heated. An anology on a much larger scale would be dead leaves that gets buried or squashed underground and over million of years serve to become fossil fuel. The vast energy does not come from the leaves themselves but from the potential energy accumulated by converting gravitational energy (through squashing) into molecular energy stored in the leaves to become a fuel.