Think about the main job if your red blood cells. if red blood cells couldn't deliver oxygen to your cells, what would be the condition of your body tissues?

The condition of your body tissues would be that they would die. If the tissues  do not receive oxygen they would die.

bal is blood alcohol level. bac will normally be higher in a person with more body fat. so the answer to your question would be, as body fat decreases, the increasing rate of bal decreases.