As far as I unterstood it (not an expert) the main entry point are epithel cells in the nasal cavity and upper respiritory track. These areas are full of blood vessel. I would guess, the infection of the lung comes from the blood vessel into the alveoles.

Short answer: No...

Longer version: as long as any diet allows your cells to survive, a virus does too, because he piggybacks on your cells methabolism. Everything a cell needs so survive and replicate, a virus will use for his own replication. Best case scenario, nothing will happen. You get sick, your immune system destroys the virus an that's it. Worst case, the diet weakens your body and this will lengthen the sickness.