The previous comment is wrong. Not only can you eat at those elevations, but you have to eat. Yes, your body is shutting down, and that includes digestion. You

The previous comment is wrong. Not only can you eat at those elevations, but you have to eat. Yes, your body is shutting down, and that includes digestion. You won't want to eat, but you have to force yourself to. Most people eat high carb, high calorie foods on summit day. Your body is burning a lot of calories at high elevations, and you have to replenish them. Your body shuts down faster if you don't regularly eat. There are lots of accounts and theories about the best foods to eat at these elevations, they are easy to search online. Search for high-elevation diets, or "foods to eat on summit day".