The study how the body uses food?

Sorry babe i don't get your question if your question is "how does the body use food" then your answer is this (when you eat, your body breaks down all of the starches, sugars, fats, etc. from food that you eat, and uses that from the food you just ate for ENERGY so you can stay alive) so long story short your body uses food for ENERGYbut if that wasn't your question then i'm sorry i don't know

Call the cops or tell an adult u trust

Answercirculatory,blood moves oxygen;