Question

Does every change in energy of the body involve work

Answer 1

Energy is that certain something inside stuff that makes everything happen. When something or somebody moves or jumps or falls or explodes or breathes or thinks or dances or does anything, it s because energy is being transformed. Energy is being transformed or changed from one type of energy to another, or, in the case of heat flow, from one place to another place.
So every change in energy of the body involve work