Purely hypothetical/academic q. if someone undergoes laserlipo/coolsculpting, can/does the body still use these dead fat cells as energy? if after the procedure you fasted, would the body just skip the dead fat cells when looking for energy?

These procedures remove or destroy the fat cells which make them unavailable for any energy production. They also never reach all the endless sites where fat cells reside.These are hidden in the support structure between intestines, between muscle groups in your extremities among other sites. I wouldn't worry about not having some fat reserves. If they are totally gone, the body breaks down muscle

Dead cells are dead cells and not a source of energy. The body absorbs and heals the area.