'Energy loss' has little meaning unless you were trying to do something with that energy.

A useful context would be in something like a car engine. Some of the energy from the fuel is lost via (for example) heat escaping from the cylinders and the engine, instead of propelling the car.

So if you were burning food to heat the room, light would be lost energy. If you were burning food to light the room, heat would be lost energy.

But if you were burning food for no particular reason (beyond 'experiment') the question is pretty meaningless, unless the intended answer is something along the lines of, 'energy is never lost to the universe, it just changes form'.