Plants don't eat or drink but can lie in bed for a long time , mainly because plants can't wake up to eat through their mouths, but they mostly have to transport nutrients into the body through the pipeline, otherwise, there has been no nutrient intake, and surely has not been in human form. Vegetable people are actually brain dead people, according to the reason is actually not necessarily able to wake up, so they and usually ordinary sleeping people are different, they need nutrition has not much, so that even if usually do not eat a lot of food through the mouth, through the pipeline to deliver some nutrient solution is also already enough. Because they don't move, even their brains aren't very active anymore, and they don't consume much. Moreover, a vegetable is actually a kind of person who relies on their nerve center to maintain life, and they won't affect their life even if they don't need a lot of nutrition. Because their vital signs are actually quite weak and they've lost most of their normal human functions. So at this point they like the fact that their nerve centers are still able to function normally, and even if they don't get a lot of nutrients, they can still lie in bed peacefully. This is because their nerve center is like a substitute for the brain that can manage and take care of the body. It is the same as guarding the sleeping protagonist, as long as the nerve center is intact, the shortage of nutrition can still be maintained for a long time. Although the vegetative person doesn't eat or drink, the family members or doctors usually break up those nutrients and put them into syringes. Then they inject the needle into the plant's body, which is equivalent to them eating with their own mouth. And it helps their digestion even more because it's liquid and will break down directly in the body. It would also replenish the needed nutrients in time, so it could be said that a plant person would not lack nutrients.
As long as the medical equipment is good, the nutrition is taken in fully on time, and the central nervous system in the body is still intact, it can always keep the vegetative person lying in bed peacefully. So don't worry too much about not eating or drinking.