Why do you need food and water to stay alive?

Question: Why do you need food and water to stay alive?
- Keywords:
  food,
  live,
  water
Asked by 293fddk22 to Yvonne, Yannis, Gonzalo, Golnaz, Ciara, Elaine on 10 Nov 2017. This question was also asked by 4L3X.
- Ciara O'Donovan answered on 10 Nov 2017:
  
  We need food to survive as it contains nutrients that we need for our body to function.. all living things need food to survive. Our bodies are about 60% water and so we need this to survive also. Water is also involved in important processes in our bodies such as digestion of food.
- Gonzalo Delgado-Pando answered on 10 Nov 2017:
  
  Yes we need food and water to stay alive. Most of the foods contain also water.

Question: Why do you need food and water to stay alive?