What does the assimilated food provide to the body cells?

Food that has been digested provides energy and building blocks to the body's cells. 

The nutrients absorbed from the small intestine, such as glucose, amino acids, and fatty acids, are carried by the bloodstream to the body's organs, tissues, and cells, where they are assimilated. 

During assimilation, cells use nutrients to perform functions such as tissue building and repair, energy production, and growth and development.