Cortisol follows a natural daily rhythm — rising before dawn, peaking in the morning around waking, declining through the day to a nocturnal low. Chronic stress flattens this pattern, blunting the morning surge and shrinking the difference between peak and trough. Dallman’s model describes a loop rather than a single push: elevated cortisol drives a pull toward comfort food, that eating lays down abdominal fat, and the fat in turn signals back to damp the stress hormones — which is what makes the cycle self-reinforcing. Separately, cortisol has been found to promote visceral fat storage directly, with central fat then producing greater cortisol reactivity.
This companion covers the normal rhythm, what chronic stress does, the health consequences, supporting the rhythm, and the eating connection to cortisol dysregulation. (4 min read)