How does the protein that you eat wind up building your muscles? How does that bowl of pasta give you energy? Why do we need to eat fat?

1. when we eat protein our body breaks it down through  digestion and then the broken down food is sent through our bloodstream and then it is rebuilt into muscle. 

2. it gives you energy because the carbohydrates break down the sugar molecules and produce energy. 

3.we need to fats because in the fat that we eat it has phospho lipid bilayers and we need that because it protects the cell membrane. it also provides insulation for the human body.