And what might be your definition of food? The sun shining life on all creation? The air that fuels and purifies? The fruits, nuts, seeds and herbs offered unto us from the palms of Ra? Or the devitalised, noxious, processed filth that inflicts only poison and decay...?
The light and air provide sustenance; therefore "they" are indeed consuming to stimulate their existence, albeit by tapping into the source of all things rather than choosing to consume secondary (or far worse) sources of cosmic energy.