Why does the immune system depends on healthy food?

Part of the whole. The immune system is one part of the miracle of a human body. For your body to work properly it requires healthy food. Try to develop the habit of eating plenty of vegetables and fruits, moderate amounts of lean meats, and plenty of water. Eat slowly and stop when you begin to feel full. Eat very limited amounts of sugar, caffeine, and alcohol. This type of diet will serve you well.
Immunity. Because food is the fuel and building block utilized by the body to make all the necessary immune system components to protect us.