Answer:
depends, if you figure out how to use a mammal or a synthetic body system to turn the food into energy and then convert that energy to heat energy only then yes, you could. but i dont think that's a thing that humans have figured out yet(although i believe its completely possible albeit very inefficient seeing as that's taking a hell of alot of energy and turning it into a more dispersible energy as well as an expirable energy source (such as in the matrix, they use humans as batteries and feed each other the remains of the former human batteries.(either that or they repurpose the remains into new humans)) but in any case its not very efficient.