After break down food may be used in the body to provide energy, as building blocks for tissue and cells, and can be stored for future use.
The body uses food for energy, for growth by making new cells and repairing or replacing tissues, may be stored by converting it into glycogen or fat before they can be stored. The main types of foods are carbohydrates, proteins and fats.
It is observed that the human population keep increasing significantly and it began to increase noticeably around 10,000 years ago.The greatest factor of this increase is the rapid development of the agricultures in lands, as well as the domestication of animals. These are the reasons why population increases at that time.
All characteristics of life rely on the sun.