Fat breakdown in response to adrenaline varies between body regions only when adrenaline directly activates its receptor; when substances that act after the receptor are used, the variation disappears, suggesting the difference is controlled at the receptor level.

Fat in the belly breaks down more easily than fat in the hips when stimulated by stress hormones, but not when you bypass the hormone receptors and trigger fat breakdown directly—so the difference is because belly fat has more hormone receptors, not because it’s more responsive after the signal gets through.