Food of light is the life energy that really keeps us alive. It nourishes us completely if we allow it. Tens of thousands of people now live exclusively on food of light. Here, light does not primarily mean the physically perceptible light, but the light from the spiritual "sun". The source of all life is pure spirit. If we voluntarily connect to this source, we can live completely from it.
We could not live without this food of light. We could not live only on earthly food.
"In the beginning was the light" is the title of a very good movie about light nutrition. Here is the trailer: