Can we survive only on raw, leafy vegetables/ grass? Discuss.

We know that animals like most of the bacteria, non-green plants and human being do not possess the ability to synthesize their own food. Therefore, they depend upon autotrophs for their food supply either directly or indirectly. The green plants (leafy vegetables/ grass) trap solar energy and manufacture their food in the form of glucose. So, leafy vegetables and grass can provide sufficient energy required for the survival of human being.