Vulcans have naturally slow metabolisms and don't require as much food or water as humans to survive. Consequently, Spock will most likely want to give the food he finds to the humans around him.

What happens to an exosuit if a character forgoes food for extended periods? Would external power sources be enough to keep it adequately charged? If so, would there still be a significant disparity between the exosuit of someone who's eating fairly regularly vs. someone who hardly eats at all?