Answer: 70%
Step-by-step explanation:
About 70% of calories are used by the body for physiological functions and what are the functions that are very important for human life. Those functions are including breathing, blood circulation, digestion and they are bonded with heartbeat and functions that are keeping person and body alive.
Most of those calories are used for metabolism and the autonomic system of the body is the one that is responsible for the functioning of those important body functions.